Throughout history, human hair has been the subject of much vanity, research, and stereotyping. Hair traits and associated medical and social implications influence our perceptions of each other and ourselves. In this sometimes hair-raising account, we explore some of the most fascinating facts in the study of human hair.

10Melanesian Blondes

Blond hair is usually seen as synonymous with Caucasian people. However, blond hair actually also regularly occurs among the Melanesian people of New Guinea and some Pacific islands. Melanesian blond hair is curly, and while it appears straw-colored, it is actually associated with a completely different gene than the blond hair common to Europeans. In addition, this very different version of blond hair is not correlated with blue eyes (the Melanesians also aren’t subject to the stereotypes that plague Caucasian blonds). The blond hair is based on a genetic mutation that affects amino acid patterns. Genetically related, but long separate, Australian Aborigines may also exhibit blond hair.

9The Not-So-Naked Ape

While proud of not being covered in “primitive” fur, humans also sport the dubious nickname of “The Naked Ape.” Chimpanzees, our closest living relatives, appear to be covered in hair compared to us. However, human body hair is actually present in approximately the same density as chimpanzees per square inch. While this might seem unbelievable, your experience is based on visual perception. Only the most significant, thickest, and boldest of human body hairs are readily visible, creating a false impression. If you take a magnifying glass to any part of your body, you will find a multitude of fine, pale hairs, which are hard to see regardless of your hair type. These hairs add up to equal the hair count of our coarser-haired primate relatives.

8Blonde Women Have More Estrogen

Hair color might not instinctively seem applicable as an indicator of human traits. However, hair color is an outward indicator and genetic phenotype component that means different things according to the gender of the person bearing it. For example, blondes are sometimes perceived as especially feminine. In fact, scientific investigation indicates that blondes have higher levels of estrogen than other females.

Blondes may thus have finer features and a more “youthful” personality than darker-haired women. Surprisingly, blond hair does not seem to relate as much, if at all, to male hormone levels, although more research could always uncover surprises. Both male and female blonds have more hair, with an average of 130,000 hairs, compared to 100,000 for brunettes and 80,000 for redheads.

7Redheads Get Hurt Easily

Redheads are often stereotyped as hot-tempered. While the jury may still be out on that particular personality trait, the science is fairly strong on the fact that redheads are definitely prone to getting sore—referring, of course, to how they perceive pain. Dentists and scientific researchers have noted that natural redheads are in fact more sensitive to pain than blonds or brunettes.

At the same time, redheads are hit with an unfair and ironic combination—they are less sensitive to the effects of painkillers than blonds or brunettes. Redheads often avoid going to the dentist, and it turns out that a dose of painkillers 20 percent higher than the norm may be needed to properly inhibit their pain reception, according to a study recently published in the British Medical Journal. Redheads are also more susceptible to skin cancer, and, oddly, never develop gray hair. Redheads may eventually turn blondish, and then pure white.

6Blonds Are Behind In Britain

British people, descended to a fair extent from Germanic and other European mainland ancestors, boast a high percentage of blonds (male) and blondes (female). While blond jokes have often targeted females, male British blonds seem to be subject to some, possibly discriminatory, variable that is restricting their professional success. A recent study in the UK looked at the possibility of discrimination against blond males in a sample of 500 CEOs from the London Financial Times Stock Exchange. Chi square statistical analysis revealed that only 25 CEOs (five percent) had blond hair. Since 25 percent of the UK population is naturally blond, this indicates a noticeable under-representation of blonds in the upper echelons of British corporations. However, redheads, who make up only one percent of the UK population, were over-represented, comprising a surprising five percent of CEOs.

5The Science Of The Beard

Beards have been celebrated as among the most distinguished male traits, although ironically they may also be perceived by some as unprofessional or informal. The science is even more interesting than the complicated sociology of beards. There are actually two types of human hair. Fine, sometimes nearly invisible, strands known as vellus hairs cover much of the human body. The more limited in extent, but far more prominent, terminal hair is found on our heads.

Facial and chest hair in men and pubic hair in both sexes is also terminal hair, making it the same type as our head hair rather than the rest of our body hair. Strongly pigmented and relatively coarse, the terminal beard hair becomes thicker in men due to testosterone. Now that we understand beards, we’ve discovered that these aspects of male beauty are also strikingly practical. Scientific research indicates that bearded men receive only a third of sun-related radiation on the areas protected by facial hair as compared to bare skin. This may reduce skin cancer risks.

4Legally Blonde, Smoking Brunettes

The comedy Legally Blonde humorously plays off the term “Legally Blind,” but research shows the ideas may unfortunately go together on a deeper level. Blonds, especially blonde females, are more susceptible to age-related macular degeneration compared to redheads or brunettes. The eye condition can cause serious visual impairment, but proper nutrition from dietary vegetable intake, along with the use of sunglasses, may help to stave it off. Blonds of both genders, like redheads, are more susceptible to skin cancer, and will often burn more quickly in sunlight. On the subject of hair color and cancer, brunettes are more prone to non-Hodgkin’s Lymphoma. Surprisingly, smoking addiction is more likely to affect brunettes, as their higher overall melanin content prevents their liver from metabolizing nicotine effectively.

3Learning Disabilities And Hair Color

Blond hair and blue eyes might be seen as a striking combination, but they could also be correlated with an increased incidence of certain medical conditions. In a study of 50 learning disabled children, 20 percent were blond. However, only 11 percent of non-disabled children were blond. The blond hair and blue eyes combination is also often seen in patients affected by phenylketonuria, where phenylalanine builds up in the body. Behan et al. (1985) suggest a higher rate of blue-eyed blonds in the dyslexic population (they were also more likely to be left-handed). Another study noted a slightly increased incidence of learning disabilities reported by blond professionals. It is believed that melanin may play a role in the development of neural circuits, and some blonds may be more subject to certain conditions as a result of their reduced melanin levels.

2Eyelash Hair Mites

While head lice are unfortunately an all-too-familiar concern, the apparently sparse eyelash hairs are the last of the human hair zones you’d examine for parasites. But while the other entries on this list tend to focus more on genetics, we must cover the unsettling fact that humans frequently have tiny, wormlike mites living in their eyelash follicles. The mites feed on waste products, including sebum, which is the only possible potential benefit to their hosts—who include nearly all humans. Rates of colonization increase with age. Eyeliner or mascara use may also increase their numbers, and overpopulation could force out an eyelash by loosening the follicle. Eyelash mite infestations can also lead to discharges, with impaired vision and eyelash loss in severe cases. Either way, being host to eyelash mites is one of the more bizarre and unexpected elements of the human condition.

1Baldness Is Linked To Heart Disease

The loss of hair, whether as a result of a medical condition or aging, is often a great source of concern. It is usually males who go bald, while women almost always keep their hair, a fact related to testosterone levels. Baldness might seem cosmetic, but a recent medical study of 40,000 men has linked balding to a much greater risk of coronary heart disease. The risk of heart disease in men with male pattern baldness was found to be 70 percent greater than in non-balding males. Different levels of baldness carried differing risk levels, from 18 percent at mild to 48 percent for serious balding. The correlation between top of the head baldness and heart disease is believed to relate to multiple factors, potentially including insulin and hormone-related variables. Interestingly, a receding hairline and hair-loss away from the top of the head was not associated with heart disease.

Ron Harlan investigates the mysteries of nature, the human body, and the bizarre findings that often crop up on this planet. He is a freelance writer, researcher and graduate student of sciences at Royal Roads University.

Most of us think of human corpses as disgusting, creepy things that we would do everything in our power to keep away from. They remind us of our own inevitable mortality as they stare back at us with blank, gazing eyes. But under certain circumstances, people have shown an incredible ability to overcome this fear. Medical examiners and forensic pathologists, for example, are trained professionals who have learned to look beyond their initial squeamishness for a good cause.

While those people are professionals doing a job they’ve been hired and trained to do, others have less understandable, much weirder reasons for hanging around dead bodies—some can’t let go of a person they lost, while others might even actually enjoy being around corpses, as is the case with necrophiliacs. The line of distinction between the two is both one of purpose and legality. Here are ten people who actually lived with corpses for a while, usually under some pretty bizarre circumstances.

10 Robert Calvin Mark

The first corpse cohabitant on our list is a Tennessee man who recently received a knock at his door. Officers had shown up to arrest him for living with a dead body in his home without notifying authorities. (Yes, that’s illegal in Tennessee.) The arrest took place on December 3, 2018, after the police received a call asking to do a welfare check.

Agents with the Tennessee Bureau of Investigation went into the home and found 72-year-old Dorris Ann Braithwaite dead on the floor.^[1] The man who lived there, Robert Calvin Mark, age 64, was arrested on the spot and is held on $750,000 bail for the crime of abusing a corpse. Doris, Robert’s girlfriend, had been dead for weeks or months, say authorities, judging by her state of decomposition.

Neighbors say they rarely saw Robert, and he largely kept to himself. They mentioned that they only really saw Robert when he came out to smoke a cigarette. Creepy.

9 Robert James Kuefler

Minnesota man Robert James Kuefler was open and honest about what he’d done, which was live with a corpse. He lived with two of them, actually, for over a year. The corpses in question were the bodies of his mother and his twin brother.^[2]

How Kuefler covered this up would have been a mystery if he hadn’t been so forthcoming. He explained to authorities and reporters that he wrote Christmas cards to other family members explaining that both were in poor health and that they couldn’t speak on the phone, and somehow, the family bought it. The man mentioned that his mother died in August 2015 and that his brother died a few months before that, and he just couldn’t let go. Traumatized, he kept both bodies until he was found out in September 2016.

Police say that the brother’s body was mummified and that the mother’s body was basically a skeleton by the time they got there, as revealed by court documents. It took several weeks to identify the bodies, but the medical examiner said that, while they couldn’t find an exact cause of death, the deceased did, in fact, die from natural causes, and murder was ruled out.

8 Matthew Schmarr

In 2017, when the authorities were finally able to open the door of the residence of a New Jersey man named Matthew Schmarr, they had no idea of the shocking scene they were about to uncover. There, they found two beds across from one another, one with Mattehew Schmarr, 35, and another with the dead body of a 52-year-old woman. She had been dead for three days.^[3]

The story turns out to be rather tragic. On March 18, Schmarr was babysitting for a friend when he decided to drive to another town to buy various drugs, including crack and heroin, leaving the child in the home in the care of the 52-year-old. The woman was alive when he returned, but by the time the child’s mother picked the youngster up, Schmarr had discovered that the woman was dead.

Afterward, he tried to manipulate the scene, arranging it to make it look like a suicide, and sold the woman’s laptop to get rid of evidence (and probably make a little cash). When police first showed up at the door, no one answered. They retrieved a key from Matthew’s neighbor and were able to gain access to uncover their terrifying find.

7 Doris Kirby

People who live with dead bodies aren’t always men, and they don’t always do it intentionally, or even consciously. Sometimes, the elderly end up doing so completely incidentally and tragically can’t help it. Such is the case with Doris Kirby, whose husband died in 2014 after suffering from numerous health problems.^[4] The couple lived in poor health in Alabama, and she stayed by her husband until the end.

But Doris Kirby suffered from Alzheimer’s disease, and her husband took care of her at home. When he died, Doris was already so far gone that she lived with her husband’s corpse for months before the police did a wellness check. When they peered through a window into the house, they saw the dead man inside. They also found two dogs that had starved to death. Poor Doris Kirby had progressed hopelessly far in her Alzheimer’s disease and simply couldn’t make it without him. But they stayed together as long as they could, and that counts for something special, I think.

6 Rhode Island Man

Then, in a twisted case of events, 1,900 kilometers (1,200 mi) away, the same thing would happen again only a few days later, when a 71-year-old man called the fire department. He was in the advanced stages of Alzheimer’s disease, and the reason he called was unreported, but upon their arrival, the fire department discovered his wife’s dead body, which had been in the basement for at least two days. He was living with her corpse and completely unaware of it, tragically.

Yet again, the authorities found a dead dog in the basement, but they saw no signs of foul play and expected that both the dog and the 67-year-old woman had died of natural causes, after which the man just stayed with them.^[5]

5 David Hall

A man in Monroe County, Michigan, was arrested for living with the body of his deceased girlfriend for a month. The man, David Hall, was 49 years old, and his girlfriend, Kandance Simmons, was 56 when she died there in December 2017, but police wouldn’t make the discovery until January 2018. Simmons had a history of health issues, and the police saw no signs of violence or foul play, yet again, but David just decided to keep her corpse tightly locked up in his bedroom.

When the police entered the apartment, they found Kandace’s corpse on the bed. Hall was, of course, arrested and brought up on charges of concealing a death. Authorities say that David Hall had absolutely no explanation for why the corpse of his girlfriend had been in his home just lying there for a whole month.^[6]

4 Alfred Guerrero

In October 2015, the police responded to a call about a terribly foul and rancid odor coming from a hotel room in Ontario, California. When they arrived and knocked on the door, the man who had lived there for over two years, Alfred Guerrero, opened the door, and they asked him about the smell, noticing flies everywhere in the room. The man refused to answer any of their questions, so they took him outside and performed a check on the hotel room.

Inside, they stumbled upon a dead body somewhere in the room and phoned for detectives to investigate the scene. The corpse had been there for several days. There were no obvious signs of a cause of death, even though it was extremely suspicious that he was not at all forthcoming and would not talk to police. Even with this, the police let Guerrero go and released him without charges.^[7]

3 Michael Eugene Sticken

The date was May 13, 2015, and the police were called to the residence of Joyce Willis, who lived with her son, Michael Eugene Sticken, a Florida man. As they approached the door, they were immediately hit with a pungent odor that immediately appalled them. They instantly knew something was wrong.^[8] The officers walked in to find the 81-year-old Joyce dead, just sitting there on the couch. It was straight out of the movie Psycho.

As it turns out, Michael kept her there so that he could survive off her Social Security checks. The medical examiner did an autopsy and concluded that she had been dead at least a month and no more than four months. Michael Eugene Sticken was placed under arrest and taken to the county jail.

2 Dennis McCauley

In April 2013, yet another Michigan man was surprised by a knock at the door when the police showed up to ask questions. The 64-year-old, Dennis McCauley, would be arrested and brought up on charges for failure to report a death when police discovered he had been living with his deceased girlfriend for months.^[9] He was also charged with larceny, uttering and publishing (which is basically a bit like forgery), and identity theft, as he was collecting and using her Social Security checks.

When a friend noticed that the dead woman, Ann Marquis, hadn’t been around for months, she started to fear that her friend might be dead, so she asked Dennis McCauley, the man she lived with, where she’d been. McCauley told the woman that Ann had moved out. After Ann died, McCauley fell behind on the bills and went on that way for months with her dead inside the trailer. A court officer finally showed up to knock on the door to serve an eviction notice, and no one answered, but when he peered inside the window, he saw her corpse sitting inside, decomposing.

1 Belgian Woman

The Belgian authorities didn’t release the name of the woman who committed the act, but the dead man’s name was Marcel H., and he was found as mummified as she was bereaved. The unnamed woman was Marcel’s wife when he died in November 2012 and simply could not handle the loss at 69 years old. Marcel was gone, and there was nothing she could do about it. But that didn’t mean she had to let him go—so she kept him . . . for a year. The unnamed Belgian woman decided to keep her husband as if he had never died. She let him “sleep” in the bed with her as if nothing had happened, as if he was still there, still present, still a thinking, living person.^[10]

But she hadn’t paid the rent in over a year. The man mummified during that time, and the body didn’t smell anymore. His corpse was found dressed and laid in the bed, where she slept. She simply didn’t care. She just wanted her husband to still be there, and that’s all that mattered to her. Marcel H. would end up spending both his life and death with his living wife.

I like to write about weird, dark stuff, and history.

We have plenty of things living on and in us. Most of the organisms that reside on or in us are not only perfectly natural but perfectly healthy as well. From the bacteria and fungi that dwell on our skin to the microflora that call our gut home, most of these creatures actually help us to protect ourselves, to survive, and to perform the basic necessary bodily functions of the human organism.

Occasionally, we’re reminded of the damage that can be done by something growing in our bodies, like when a terrifying flesh-eating microbe decides to eat away at us. Other times, small, unseen organisms can hijack our minds and alter our behaviors and even our perceptions. But beyond the usual pathogens, sometimes the organisms that grow on or in us are actually visible (or at least their effects are). Here are ten cases of infestations that actually took place inside people’s bodies.

10 The Hand

Barnacles are crustaceans that inhabit marine waters. Around 850 species of barnacles are largely immobile and don’t do much at all; think of the kind you see attached to the hulls of ships. These barnacles contain an extremely strong adhesive paste that they use, almost like cement, to attach themselves to things in such a way that it requires tremendous force to remove them. Other species of barnacles are internal parasites that infect other crustaceans and can seriously threaten ocean life from time to time.

A man named Chris Johnson would one day end up seeing a doctor about a strange growth in his hand that had become seriously concerning. Not knowing what the growth was, the doctors took samples, which they tested. They never expected that they would find barnacles growing inside the man’s hand—but that’s exactly what happened.^[1] Both the doctors and Johnson himself were terrified.

9 The Lung

In another absolutely bonkers case of living things growing inside someone, a Boston man named Ron Sveden was having some severe chest problems in 2010. Already suffering from emphysema, Ron resigned himself to his fate, believing that he had cancer. Once one of his lungs collapsed, though, enough was enough, and Ron went in to see the doctors to diagnose him with the appropriate lung cancer.^[2]

But that isn’t what happened. Doctors took the appropriate X-rays and indeed found a growth inside Mr. Sveden’s lung, but it wasn’t a clump of cancerous cells like they were expecting—it was the humble beginnings of a pea plant. Months prior, Ron had been eating, doctors hypothesized, when he must have taken a pea down the wrong tube and into his lung. The pain that ensued was from the pea being lodged inside his lung, but it didn’t stop there. The pea began to sprout and actually grow, infesting the inside of Mr. Sveden’s body.

8 Fir Tree

A very similar and slightly crazier incident hails from Russia in 2009. Yet again, an individual was pained in their chest, specifically their lungs, and something was removed. What exactly was that? The humble beginnings of a growing fir tree, which was apparently 5 centimeters (2 in) long. The doctors who performed the operation said that they were 100-percent certain that a tumor in the man’s lungs was cancer, but when they went to open him up, a sprouting fir tree was what was found inside.^[3]

While no one aside from the surgeons and the patient verified the claim, considering the story of Ron Sveden in the United States, it’s very possible the men were telling the truth. Seeds sprout without sunlight, and plants only really need light to photosynthesize once leaves begin to grow.

7 Maggots

Next on the list is an extremely unusual case of maggot infestation, one that ended up being most definitely a good thing. Pham Quang Lanh was a 28-year-old laborer working as a guest worker in Malaysia, outside of his native Vietnam, when he an iron bar fell off a building and onto his head in 2015. Fortunately, Lanh survived the injury, at least in the short term, thanks to surgery and a titanium plate that doctors were able to implant into his head.^[4]

But the story doesn’t end there. Lanh was in pain, and the site where the plate was inserted was swelling and generally not looking good. However, thinking it only a minor infection, he didn’t seek treatment. His family decided to take a closer look, and that’s when they discovered live maggots eating away at Lanh’s head.

In an unusual twist, while the man did, in fact, have a maggot infestation in his head, he also had a very bad infection—the kind that eats flesh, leading to necrosis of the skin cells, which can ultimately be lethal. But Pham Quang Lanh survived long enough to have the site treated because the maggots were eating away at the necrotic tissue that developed from the infection, which means the maggot infestation ultimately saved the man’s life. Talk about disgusting luck.

6 More Maggots

Believe it or not, the stroke of luck that Lanh had isn’t exactly unusual. Maggots can be very, very efficient nasty-bacteria-eating machines and can devour infections for our benefit.^[5] Not only is this reality, but it’s medicine, as doctors are willing to employ maggots when other options have run out. This almost sounds like some bizarre quack medical practice out of the Middle Ages, one that might have been used to (wrongly) fend off the Black Death, but no, this is current, modern-day medicine.

In 2012, a team of doctors at a hospital turned to maggots for a man named Waclaw Tyszkiewicz, who was suffering badly from an infection in his foot that was quickly spreading up his leg. The infection as such that amputation was the only choice—aside from literally dumping maggots on the infection site; and that’s exactly what they did. Once a week for three weeks, 800 maggots were applied for 36 hours, after which the area was doused in hydrogen peroxide, and guess what: It worked. While Waclaw still lost a toe in the ordeal, he managed to keep everything else and heal up nicely. Thanks to maggots, he was able to keep walking.

5 Morgellons

Morgellons disease is an odd one. A part of the problem in understanding this unusual skin disease is that different studies have drawn radically different conclusions over time, leading to a lot of confusion pertaining to what’s actually going on with the poor people who suffer from this extremely rare condition.^[6] Most of the symptoms are pretty common and shared with other diseases and syndromes, such as depression, fatigue, and skin rashes, but some of them stand out as downright mortifying: People with Morgellons disease begin to feel like insects are crawling inside their skin or like there is movement inside them beneath the skin.

From there, it just gets even more terrifying, as fibers actually begin to appear under the skin. The fibers are long and stringy, often black, and many of them have been tested and turned out to be cotton. Medical science doesn’t know for sure why this happens to some people (mental illness has been blamed), but it does.

4 Bird Mites

Bird mites are tiny, eight-legged, parasitic creatures that live on the blood of warm-blooded hosts—and they also sometimes make their way inside a person and decide to call them home. They sometimes dig into the noses of humans, too.

The most terrifying thing about bird mites is their symptoms, the main one being feeling like insects are crawling underneath your skin, which is to be expected. But bird mite infestation also causes severe psychological anguish as well as the usual depression.^[7] Fortunately, such mites can’t complete their life cycle inside human beings alone and thus must travel back into birds (where they come from) in order to do so.

3 Scabies

Scabies are awful for anyone to get—tiny mites infect the skin and cause the host organism extreme discomfort. Even worse, by the time a person infected with scabies notices any symptoms, it’s already too late, and they’ve become an infestation, as there is an incubation period of several weeks. Scabies can be treated most times with the simple application of a topical ointment, but sometimes, due to just the nature of these little critters, they can spread like crazy and wreak havoc.

One such instance was something straight out of a Stephen King book or movie. An infestation of scabies went absolutely crazy and even ended up being fatal.^[8] The outbreak took place, tragically, in a memory care facility, a place where people are kept when they have impairments such as dementia or Alzheimer’s disease. Between 2013 and 2016, the SouthTowne Memory Care facility in Eugene, Oregon, had an outbreak that it would ultimately be sued for mismanaging, one which infected at least a few dozen people.

The painful, unceasing itching that scabies causes is absolutely mortifying. One 83-year-old woman named Pat Lancaster had left the facility but ultimately ended up dying a few months later. Between the time she left and the time she died, she had gone to the hospital, where doctors were shocked to see her condition so poor, with scabies so deeply embedded. They treated her and were able to remove the external scabies with ointments, but the mites had gone deep inside her, and she ended up dying from them. She was found having scratched massive chunks of skin off in a terrifying fashion. Scabies is no joke—it can kill you and should be taken very seriously. Two others also died in the outbreak.

2 Cockroach

Did you know that sometimes, cockroaches actually crawl inside people? They do, and the ear is a likely place of entry. When cockroaches are afraid, usually of weather changes or a perceived predator, they hide, sometimes inside your ear hole. They make themselves at home, and even more terrifyingly, sometimes, they’ll choose your ear as a perfect spot to lay their eggs. The fact that they generally can only go forward and not backward means that they probably won’t come out on their own.

In one terrifying situation, a woman from Florida named Katie Holley was sleeping one night in 2018 when she felt something seemingly cold slide into her left ear canal. Attempting to solve the problem and thinking the object was inanimate, she put a Q-tip into her ear and tried to figure out what it was—and that’s when she felt it move.^[9] That’s when things got even more awful: She removed the Q-tip to find what appeared to be legs on it.

It would take Katie a full nine days to get every piece of the roach out of her ear. She initially went to the emergency room, where most of the cockroach was removed, but then a week went by, and something just wasn’t quite right with her ear. After an uncomfortable several days, she decided to follow up with her doctor, who looked inside her ear, only to find more of the roach. Her doctor then removed the remainder, and her nightmare was finally over.

1 Super Gonorrhea

Just the name itself sounds absolutely horrifying: “super gonorrhea.” Super gonorrhea is an extremely antibiotic-resistant strain of the regular gonorrhea bacterium which is currently untreatable and spreading around the world slowly but surely. Unlike some other STIs, super gonorrhea is also transmittable through oral sex, making it a bacterium that’s relatively opportunistic.

In what has been called the worst case of super gonorrhea so far, a British man caught the bacterium after sleeping with a woman while on a trip to Southeast Asia in 2018. It was so bad that UK health officials attempted to track down his other sex partners themselves to warn them. Antibiotics failed to treat the disease, leading officials to worry what lies in the future when it comes to combating these critters that might infest and parasitize us. The complete inability to treat this man’s case with the go-to antibiotics was a first.^[10]

More often than not, we look back at the religious practices of old and even the ones still carried out today with anything from a raised eyebrow to a nauseating sense of moral disgust. It’s been fairly well-documented in scientific literature that humans act out in violence as a last resort, trying to stake their claims to social status or simply trying to survive.

Religion usurps this aspect of human existence, blending status and survival and giving it away to proposed supernatural forces which people have sought to please to receive blessings and good fortune since time immemorial. Here are 10 civilizations which engaged in one of the weirdest religious practices of all, the sacrifice of children.

10 Babylon

Finding itself dead center in the birthplace of civilization, Babylon was a megalithic settlement and one of the most powerful forces of the ancient world. They sacrificed human beings to their chief deity, Marduk, as well as others like Anu, a deity of the city Uruk, during the later years of the Babylonian Empire. Annual fire festivals were held where they would sacrifice children to Anu.

It’s safe to say that human sacrifice was a staple during the entire existence of Babylon, with the first mention of the city’s existence in the 23rd century BC. It remained a powerful city and empire at times until it was taken by Alexander the Great in 331 BC. After that, it could never quite recover its former glory.^[1]

9 Aztec

The Aztecs are probably the society best known for engaging in human sacrifice for religious reasons. In October 2017, archaeologists unearthed a rare find, a cylindrical pit specifically dug and lined with volcanic rocks centuries ago for a sacrifice to the gods of the Aztecs.

Tenochtitlan was an ancient Aztec city which now lies in the heart of Mexico City. The find came at the foot of Templo Mayor, an Aztec temple in Tenochtitlan. It is believed that this child, known as Offering 176, was sacrificed sometime in the 1400s.

This was a time of Aztec expansion when many children were sacrificed to their gods. Most likely, Offering 176 was killed to appease Huitzilopochtli, the Aztec war god, and bring favor to those living in the city.^[2]

8 Canaan

Canaan is the all-encompassing term for the land which was in modern-day Lebanon, Syria, Jordan, and Israel. The Holy Bible is replete with references to an ancient Canaanite god named Molech (aka Moloch) to whom human sacrifices were both the norm and seemingly plentiful.

Molech was even referred to as the “god of child sacrifice” by some. This deity was thought to be very well pleased with offerings that burned living people, notably children, in a fire.

In The Holy Bible, the Book of Leviticus even forbids this practice. Leviticus 18:21 says, “Neither shall you give any of your offspring to offer them to Molech, nor shall you profane the name of your God; I am the Lord.”^[3]

7 Israelites

Before the decree in Leviticus, the Israelites often practiced human sacrifice, which included children, sometimes even to the foreign god Baal. We find further scriptures, such as those in Kings, which claim that the Israelites worshiped false gods and engaged in the ritual killing of human children.^[4]

The Bible describes the children of ancient Israel as being used much like animals for burned offerings, sometimes to even appease the Judeo-Christian god Jehovah. Some scholars have vehemently denied these allegations, though the descriptions are right there in the works surviving from ancient times.

However, it should be noted that human sacrifices were largely taboo and violated religious law in the majority of the Judeo-Christian religions.

6 Olmec

The Olmec civilization was one of the oldest large settlements in prehistoric Mesoamerica. Their culture and sphere of influence spanned much of southern North America, including the area which encompasses the modern-day countries of Belize, Costa Rica, El Salvador, Honduras, and Guatemala.

The evidence is fairly damning for the Olmec people. They are believed to be the first known Mesoamerican culture to practice human sacrifice. They’re significantly older than other cultures from the early Americas.^[5]

Around 300 BC, the Olmec people mysteriously vanished. The humid rain forest ate away the bones of the people who’d previously lived there. All we have left are the relics of their former culture.

Yet we do have evidence of child sacrifice in ancient Mesoamerica. Thousands upon thousands of bones have been recovered from various sites, including Midnight Terror Cave in Belize and the sacred shrine of El Manati. This culture sacrificed thousands of children to their gods. The bones of these children—along with those of many women—have been left behind for us to find.

5 Maya

The Mayan civilization came about some 1,500 years after the Olmec and carried on the practices of human sacrifice to their gods as well. Archaeologists digging in the Guatemalan city of Ceibal, which reaches way back to the times of the Mayan culture, have discovered something truly bizarre—obsidian stones buried at the places of their child sacrifices to their gods.

Obsidian is a type of dark natural glass, usually jet-black in color, which is formed when lava cools rapidly. The Maya believed that obsidian was a divine stone.

The Maya would sacrifice small children to the gods, whom they believed were empowered by the blood of children. Then the Maya buried these youngsters face-to-face in a grave, often with obsidian.^[6]

4 Toltec

What other cultures did on a small scale, the Toltec civilization did on a massive scale. Many civilizations inhabited the southern part of North America over time, and the Toltec came right before the reign of the Aztecs in modern-day Mexico. They dominated the area from the 10th–12th centuries AD, and the sacrifice of live children was apparently a staple of their culture like the others before them.

Near Tula, Mexico, a mass grave was uncovered during construction which contained the remains of at least 24 children. All the evidence was there of a mass killing and child sacrifice to the gods.

The bodies are believed to have been killed and buried sometime between AD 950 and AD 1150.^[7] Compared to our significantly less violent world of today, this was definitely an unusual culture and perhaps gives us a glimpse into the world of the past and the human race’s savage tendencies.

3 Inca

The Incas stand apart from most of the rest of the Mesoamerican cultures in the world of human sacrifice in that they seemingly only sacrificed children and never adults. This practice was still going on by the time that European settlers arrived.

The strongest, healthiest children were chosen intentionally as they were thought to better please the gods. It was an honor in Incan civilization to be chosen as a sacrifice or to be a member of that person’s family.

Although their population was smaller than other Mesoamerican cultures, the Inca Empire was widespread, spanning at least 4,000 kilometers (2,500 mi) at its largest. Child sacrifice quite obviously permeated the Mesoamerican world of prehistory. For better or worse, the European colonists tried very hard to stop these practices upon their arrival, though such rituals often continued in secret.^[8]

2 Teotihuacan

Many Mesoamerican cultures built megalithic structures on which they would perform their macabre human sacrifices. The Pyramid of the Moon was one such structure in Teotihuacan, Mexico, where the Mesoamerican civilizations who lived there long ago would tear the hearts out of children and sacrifice them to the gods.

The pyramid structure is approximately 2,000 years old, and the site contains the remains of many children who’d been sacrificed by this ancient culture. Strangely, the people who lived in Teotihuacan left zero clues as to what their culture might be about—no hieroglyphs or writing.

As was common with early Mesoamerican cultures, the Teotihuacanos just seemingly disappeared and we can’t quite figure out why. Centuries later, the Aztecs referred to Teotihuacan as “the City of the Gods.” The Teotihuacanos had left their structures completely intact for others to find later.^[9]

1 Celts

When the Roman Empire expanded, it stopped human sacrifice, a practice largely taboo in Greco-Roman culture with few exceptions. Most Roman writings show that they felt morally superior by not engaging in human sacrifice. One group that the Romans called the Gauls, otherwise known to us as the Celts, ritually killed children in much of ancient Europe.

The Celts were a brutal but loose-knit band of tribes who would occasionally join forces to fight off the invading Romans. In warfare, the Celts would behead their enemies and embalm the severed heads as trophies to take with them. Of course, this also scared off would-be enemies as an act of psychological warfare.

So it should come as no surprise that such a hard-core ethnic group would occasionally practice child sacrifice to appease their gods. Roman authors galore, including Julius Caesar, document the practice and their abhorrence of it at great length.

Recent excavations of Celtic sites have turned up mummies of sacrificed children as well as structures for human-made “fountains of blood” where the drinking of blood and cannibalism would take place.^[10] The Celts were a terrifyingly violent culture, and these practices show just how brutal humankind can be if left to their own devices and cultures.

We’ve said it before, and we’ll say it again: The human brain is amazing. In the words of neuroscientist Vilayanur Ramachandran, it’s a “three-pound mass of jelly you can hold in the palm of your hand,” but it can “contemplate the meaning of infinity, and it can contemplate itself contemplating on the meaning of infinity.” As it’s the most complex organ in our bodies, you can bet there’s no shortage of strange stories about the human brain.

10 Brains On eBay

Here’s a story with all the makings of a Gothic novel, complete with a mental hospital, human organs, and a ghoulish grave robber named David Charles.

Charles didn’t actually dig up any coffins, but he did break into the Indiana Medical History Museum on several occasions. From the 1840s right up to the 1990s, the museum was the site of the Central State Hospital, a psychiatric ward that performed its fair share of autopsies. After the bodies were cut up, the brains were jarred and locked away in a warehouse—a warehouse Charles later slipped into repeatedly.

After pilfering six jars of human tissue, Charles unloaded his goods to an eBay fence who sold them to a San Diego man for $600. The buyer liked “to collect odd things.” He also had a code of ethics. While he didn’t mind breaking federal law by buying human organs, and while he didn’t care about violating eBay policies on body parts, he did have problems with buying stolen property. Neither Charles nor his eBay middleman had the brains to remove the museum labels from the jars.

Figuring something crooked was going on, the San Diego buyer notified authorities. After tracking down the eBay seller, Indianapolis police officers set up a sting operation. The plan was for Charles, who’d recently snatched 60 more brains, to meet up with his eBay buddy at a local Dairy Queen. And on December 16, cops swarmed the restaurant parking lot, successfully bringing down the Indiana Igor.

9 The Cordless Drill Skull Operation

Marian Dolishny was dying. Thanks to a fair-sized tumor, he was suffering epileptic seizures, and if he didn’t do something about it soon, he’d go blind. Unfortunately for Dolishny, he couldn’t just visit the local hospital and schedule an operation. It was 2007, Dolishny lived in Ukraine, and due to a labyrinthine bureaucracy and massive underfunding, the healthcare system was a mess. No one could remove his tumor, and things were looking grim when suddenly an elderly British superhero showed up to save the day.

One of the UK’s best neurosurgeons, Henry Marsh had been visiting Ukraine at least twice a year since the early ‘90s. After meeting people with massive growths on their heads, Marsh realized he couldn’t fly back home and forget what he’d seen. So he sent disused supplies from his hospital in Tooting to Ukrainian doctors. Even better, he started offering his services free of charge.

That’s how Marsh and Dolishny met. But just because the Ukrainian had a great surgeon didn’t mean the operation was going to be easy. Marsh lacked access to the state-of-the-art equipment required for such procedures. However, the best doctors are like musicians—they’re talented, passionate, and can improvise on the fly. Marsh went to a local store and bought a $67 cordless power drill. He then operated with a gadget you keep in your toolbox.

What’s even crazier is Dolishny was awake for the whole thing. No qualified anesthetists were around, so Marsh just used a local anesthetic. And since Dolishny was awake, Marsh talked to him the entire time, making sure he wasn’t screwing up the man’s brain.

Before Marsh could finish the procedure, the drill’s battery died. Where a lesser surgeon would’ve panicked, Marsh kept on working, finishing up with his gloved hands and saving Dolishny’s life.

8 Strange Stories Of Ancient Brains

Your brain is 60 percent fat, and thanks to all that blubber, it’s the first organ to melt away after you die. That’s why archaeologists find so many skulls but so few brains. Most of them liquefied long before we could dig them up.

But every so often, scientists discover a brain dating back several thousand years. For example, the some of the oldest brain tissue ever discovered, around 8,000 years old, was found in eastern Florida, preserved under thick layers of peat. But while they’re not as old as their New World counterparts, the ancient brains of Europe carry much more interesting stories.

Our first macabre tale is the story of the Heslington Brain, the oldest known brain in Great Britain. In 2008, the University of York was expanding its campus when someone stumbled over several pits dating back to the Iron Age. After prodding around, archaeologists found one hole containing a skull, a jaw, and two neck vertebrae belonging to the same deceased Brit. When the skull was opened, scientists found the yellowy, shrunken remains of a 2,500-year-old brain. The muddy environment had kept it safe from decay. Marks on the vertebrae indicate that the body’s owner had been hanged and beheaded, possibly as part of a ritualistic murder.

Only slightly less morbid is the tale of the 4,000-year-old Turkish brain found in the Bronze Age settlement of Seyitomer Hoyuk. This brain looks like a charred log someone pulled out of a bonfire. That’s probably because it belonged to an unfortunate Turk who was minding his or her own business when an earthquake wrecked the entire village, bringing down a rain of rubble. Then, a fire broke out, incinerating everything and boiling said brain in its own juices. But while a bubbling brain sounds disgusting, this rapid evaporation of liquid coupled with nutrient-rich soil and elimination of oxygen via the flames ensured this charbroiled organ survived for thousands of years.

7 Unlocking Lenin’s Brain

Vladimir Lenin was a prolific writer and a serious philosopher. He also successfully overthrew a government and installed himself as unquestioned dictator. But was he a genius? Soviet scientists certainly thought so.

After the Premier died in 1924, Russian researchers were itching to cut open his skull and study his brain. They wanted to show the world Lenin was one of the smartest men on the planet. So after removing the brain, they plunked it in a jar of formaldehyde and stuck it in the V.I. Lenin Institute while they searched for the right expert to examine the organ. Two years later, they decided Oskar Vogt was the man for the job. The only problem was Vogt was German, and the Soviets didn’t want Lenin’s brain leaving Moscow.

In a typical Soviet compromise, officials gave Vogt one little sample to take back home. If he wanted to see the rest of the brain, he had to come to Russia. So for the next several years, Vogt visited the Moscow Brain Institute, but some Soviets weren’t too happy with this foreigner fondling their comrade’s cerebrum. Even worse, Vogt was telling people Lenin’s brain resembled a criminal’s.

Ticked off, the Soviets planned to fly to Berlin and take back the sliver of brain they’d lent the man, but Adolf Hitler fired Vogt from his position before the Russians could get their sample back. Nobody knows what happened to that little piece of Vladimir’s brain.

The Soviets cut the rest up into tiny chunks and dyed the pieces different colors. After the fall of the USSR, Russian scientists released a paper detailing the results of their nearly 70-year-long study. They had found nothing interesting at all.

6 The Woman Who Remembers Everything

Can you remember where you were on a randomly selected date 30 years ago? Say, the afternoon of September 20, 1985? Assuming you were even alive then, chances are good you’re drawing a blank, but Jill Price remembers that day perfectly. She was wearing a big hat and eating garlic chicken with her dad at one of her favorite restaurants. And if you picked some other random day, she could do the same exact same thing because Jill Price remembers everything.

Jill has a rare condition called hyperthymestic syndrome, which gives her a super-powered memory. While scientists are still trying to understand Jill’s mind, they believe her elephantine memory has something do with several areas of her brain that are three times bigger than average.

Thanks to her special brain, Jill can remember most everything that happened between her 9th and 15th birthday. And after that? She couldn’t forget anything if she tried. But strangely, if you asked her to memorize a poem, she probably couldn’t do it. Jill’s semantic memory isn’t all that strong, but her episodic memory, the part that remembers personal events and emotions, is perfect. And that’s actually a big problem.

In addition to remembering cool facts, Jill remembers every terrible event that’s ever happened to her as though it happened yesterday. That’s especially hard when Jill thinks about loved ones who’ve passed away or things people did years ago. “I don’t look back at the past with any distance,” she once said. “It’s like an endless chaotic film that can completely overpower me. And there’s no stop button.”

5 How Hugo Rewired A Man’s Brain

Photo credit: Paramount Pictures

Imagine the world as a flat, 2-D panel. There is no depth perception here. When pouring a glass of water and looking from above, you wouldn’t know it was full until the water spilled over. Trees would be nothing more than flat patterns blending into the background. This is the world Bruce Bridgeman lived in for 67 years until Martin Scorsese changed his life.

Bridgeman is a neuroscientist at the University of California, and until 2012, he was one of the 5–10 percent of the population suffering from stereoblindness, the inability to see three-dimensionally. In Bridgeman’s case, his impairment was caused by alternating exotropic strabismus. In other words, his eyes wandered around independently. Since he could only focus one eyeball at a time, he could never see out both eyes at once, eliminating all depth perception.

Then in 2012, everything changed. Bridgeman and his wife went to see Martin Scorsese’s Hugo in 3-D. Even though it wouldn’t do him any good, Bridgeman bought the glasses and settled in for the picture. And once the film started, images popped out of the screen. Suddenly, everything was vivid and alive. Objects and people actually stood out from the background.

What was even more amazing is when Bridgeman went outside, he could still see in 3-D. The lampposts were no longer part of the background, and a tree was suddenly a “big three-dimensional sculpture.”

Scientists think Bridgeman always had the ability to see 3-D, but his brain just needed a wake-up call. As he stared at the screen for 128 minutes, his eyes focused on the movie, and suddenly his visual cortex just clicked.

Obviously, the 3-D movie cure doesn’t work for everyone. Some need corrective surgery, some spend hours in therapy, and others will never see the world in its full glory.

4 The Man Who Could Only Say One Syllable

Born in 1809, Louis Victor Leborgne struggled with epilepsy for years before things got even worse. At the age of 30, Leborgne lost the ability to speak. He could say just one syllable: “tan.” If you asked for his name, he’d say, “Tan tan.” If you asked him his favorite food, he’d say, “Tan, tan.” If you asked him the time, he’d say “Tan tan,” but he’d show you the correct time using his fingers. Louis Leborgne wasn’t stupid. He just couldn’t talk.

Unable to communicate, Leborgne checked in to a Parisian hospital, where he spent the next 21 years of his life. He morphed into a rather disagreeable person. He’d monosyllabically argue with staff and even steal on occasion. If Leborgne got especially angry, he could toss around a few swear words, though he could never curse when calm and composed.

Things got worse when his right arm and leg suddenly became paralyzed. Frustrated, Leborgne stayed in bed for seven years, and in 1861, he developed a horrible case of gangrene in his right side. Hoping to save Leborgne, the hospital brought in surgeon Paul Broca. The operation came too late, and Lebornge died on April 17, aged 51. However, his brain still had an important part to play in the world of neuroscience.

After examining Leborgne’s brain, Broca discovered a nasty lesion in the frontal area of the left hemisphere, a region later dubbed Broca’s area. After performing additional biopsies on similar patients, the doctor knew he was on to something big. For a while, scientists had been debating whether individual parts of the brain controlled specific functions. Now, Broca had proof that the front left hemisphere was responsible for language.

It also seemed the area was divided into multiple regions serving different functions, like language production and language comprehension. That explained why Leborgne could understand as many words as anyone else though he could only pronounce one.

Broca was right on the money, and his discovery revolutionized neurology. Leborgne’s brain now floats in a jar at the Musee Dupuytren in Paris, where anyone can come and visit it.

3 Brain Teeth And Brain Feet

Early in 2014, a four-month-old Maryland baby made headlines thanks to a rather unusual brain tumor. During an operation, surgeons found the baby had a craniopharyngioma, a growth created by the same cells that make our teeth. There were actual teeth growing in the baby’s brain. Doctors safely removed the toothy tumor, but this wasn’t the first case of its kind.

In 2008, Colorado doctors discovered Tiffinie Esquibel’s unborn baby Sam was suffering from a brain tumor. After inducing labor, the doctors took Sam into surgery, and what happened next sounds like a scene from a horror movie. When Dr. Paul Grabb cut open the tumor, a human foot popped out of Sam’s head. When the surgeons got over their shock, they dug a little deeper and actually found a hand and even a thigh.

Most doctors believe Sam was suffering from a teratoma, a tumor that often produces creepy body parts in places they don’t belong. As awful as that sounds, it’s way more comforting than the other theory doctors considered. A few suspected Sam might have a condition known as fetus in fetu, meaning he might have absorbed a twin in the womb, and his sibling was feeding off Sam like a human parasite.

2 The Man Who Loves Johnny Cash

“Mr. B” is a 59-year-old Dutchman who’s battled severe OCD for 40 years. Desperate for a cure, he agreed to try deep brain stimulation, a treatment involving surgical implants that zap the brain with electric currents.

Just as Mr. B had hoped, the shock therapy worked, greatly reducing his OCD, depression, and anxiety. However, the treatment had a really weird side effect. It turned him into the world’s biggest Johnny Cash fan. Before the surgery, Mr. B was a casual music listener who liked Dutch music, the Beatles, and the Rolling Stones. But after the treatment, Mr. B bought every Johnny Cash CD and DVD he could get his hands on. He won’t listen to anything else.

Scientists know the implants are responsible because every time their batteries start to die, Mr. B stops listening to his Johnny Cash albums. Yet as soon as doctors recharge the implants, he starts walking the line again, devoting himself solely to the Man in Black.

1 The Family That Can’t Fall Asleep

Italian physician Ignazio Roiter married into an old Venetian family, but unbeknownst to the good doctor, there was something horrifying about the clan’s history. Roiter’s first glimpse of the familial terror came in 1973, when his wife’s aunt developed an inexplicable sickness. All of a sudden, she couldn’t fall asleep. Soon, she was stuck in an agonizing limbo between unconsciousness and waking life. Completely exhausted but unable to rest, she lost the ability to walk and gave up on conversation until she died a year later.

In 1979, another aunt died of the same mysterious disease. Suddenly, someone remembered an old grandfather who’d passed away under similar circumstances. Curious, Roiter scoured records at the local church and nearby mental asylum. After finding multiple instances of relatives dying sleepless deaths, he was convinced a genetic disease was at work. And when an uncle named Silvano died of fatigue in 1984, Roiter got a chance to find out for sure.

Roiter took the man’s brain to two American specialists. After analyzing the organ, Dr. Pierluigi Gambetti found the brain was full of tiny holes. According to a second doctor named Stanley Prusiner, a mutant gene had activated a group of misinformed proteins called prions. These rogue molecules took on virus characteristics and started infecting other proteins, turning the brain into a war zone and shutting down important bodily functions like sleep.

There’s no cure for fatal familial insomnia. If that mutant gene activates the abnormal proteins, the carrier is doomed to a sleepless haze. As of 2010, scientists have found at least 40 families battling this illness. Until scientists do cure the disorder, people like Roiter’s relatives will never rest—not until that final big sleep.

Nolan Moore would dance and be merry, his life would be a ding-a-derry, if he only had a brain. If you want, you can follow/friend him on Facebook or send him an email.

Parasites, bacteria, and viruses have been the scourge of humanity as long as we have been here, but disease has reshaped our history and influenced our evolution. Parasites helped give our immune systems the boost it needed to get up and running, and the humble bacterium has helped dictate the form this planet has taken. Sometimes, it seems that we humans are simply playthings in their hands, but they haven’t just been capricious forces that toss us around like rag dolls. These microorganisms have also done incredible things to help humanity.

10The Viruses We Carried Out Of Africa Helped Us Survive

Thanks to the science of viral molecular genetics, we now know quite a bit about the bugs that infected us along our evolutionary path, and we have found that these hitchhikers have done quite a bit to help us along the way. For example, it was the evolutionary pressure they placed upon our immune system that made it as robust as it is today. Additionally, viruses may have played a role in the loss of specific receptors that we once possessed on the surface of our cells that infectious agents could latch onto and use to cause disease. By ridding the human body of this source of disease, viruses created a safer environment for themselves, benefiting everybody involved.

But they may have also played a role in ensuring that, among competing hominid species, it was Homo sapiens that came out on top. While our species was developing, disease and parasites encouraged genetic diversity and weeded out the unfit. Once the first Homo sapiens left the continent, they brought their infectious agencies and parasites with them. If you’ve read about North American and European smallpox, you know how this goes.

While it wouldn’t have been the only factor, viral parasites would spread to other hominids like Homo neanderthalensis (Neanderthals), who wouldn’t have had any previous exposure to the new bugs and possessed a nasal structure that was less efficient at filtering air and keeping new viruses at bay. They would have devastated other hominid species, because the bugs were primed to live in similar environments, but the hominids were not primed to receive them. Models have shown that if Neanderthals had a mortality rate only 2 percent higher than humans, it would have been sufficient to cause their extinction after 1,000 years of competition. While disease was doubtless not the only factor, it would have certainly played a large role.

Most models of human disease evolution claim that they mainly evolved during the Neolithic era, after man moved out of Africa and populations increased, so there is some evidence of this selective viral pressure. Many of these early viruses have even been so successful that their genes have literally become a part of our DNA. For example, the human genome has been found to contain genes from the borna virus that were gained about 40 million years ago. In fact, scientists have isolated about 100,000 elements of human DNA that have come from viruses, mostly within what is called our “junk DNA.” The viruses that make up the majority of our junk DNA are called endogenous retroviruses, and they are so much a part of us that a scientist recently brought one “back to life” and even infected hamsters and cats with it.

9Modern-Day Medical Uses Of Leeches And Maggots

For thousands of years, the European leech (Hirudo medicinalis) was used in medicine for bloodletting purposes, treating a wide range of disorders from hemorrhoids to ear infections. The practice goes so far back in time that an Egyptian painting from 1500 B.C. depicts their use. While some nations have never stopped using them, the practice fell out of favor in the Western world with the knowledge of bacteria and subsequent focus on the germ theory for medical treatment.

In the 1970s and 1980s, though, leeches made a comeback. Cosmetic and reconstructive surgeons found that they were an effective method for draining blood from swollen faces, black eyes, limbs, and digits. They are also helpful for reattaching small body parts like ears and flaps of skin, because they draw away blood that could clot and interrupt the healing process. Leeches have saved people from amputations and may even relieve the pain of osteoarthritis. Even veterinarians sometimes use them.

Maggots, on the other hand, are nature’s clean-up crew. They’re great for eating away dead or infected flesh, revealing the healthy tissue below in a process called debridement. They have also been found to be an effective treatment for ulcers, gangrene, skin cancer, and burns, among other things.

Maggots and leeches, as gross as they may be, are so effective that the FDA classified them as the first “live medical items” in 2010, paving the way for an entire industry called biotherapy. An organization called Biotherapeutics Education and Research Foundation (BTERF) has even sprung up to raise awareness of the new uses for these old critters, and there are several companies that sell them.

8Parasites And Our Immune Systems May Have Co-Evolved To Protect Us From Allergies

Researchers studying the effects of gastrointestinal parasites have come up with an astonishing theory: After parasites first colonized our gastrointestinal systems, they evolved over millions of years the ability to suppress our immune systems. At the same time, our own bodies evolved to partially compensate for the effect.

The astonishing part, and what this means for human health, is that once parasites and harmless microorganisms present in water and soil have been largely removed from their natural environment inside of us in developed nations through the use of modern medicine, our immune systems actually overcompensate for their loss, leading to allergies and even increased chances for asthma and eczema.

This “old friends” hypothesis (sometimes referred to as the “hygiene hypothesis,” though it’s actually more of a complementary theory) has gained more support in recent years as we identify new ways microorganisms have helped us survive over the eons. Clinical trials have been conducted using worms to test against multiple sclerosis, IBD, and allergies.

The main proponent of the old friends hypothesis is Graham A.W. Rook of University College London. He first proposed it in 2003, and since then, it has also been proposed as a possible cause of some forms of stress and depression.

Some people have taken the old friends hypothesis to its ultimate logical conclusion that if removing our parasites from society has led to health problems, we should put them back. In 2008, University of Wisconsin professor of neurology John Fleming conducted a clinical study in which he infected multiple sclerosis patients with parasitic worms to test their effectiveness against the disease. Over a period of three months, patients who had an average of 6.6 active lesions around their brain’s nerve cells were reduced to an average of two. When the trial was over, the number of lesions shot back up to 5.8 within two months. In earlier trials, the parasites appeared to have positive effects upon ulcerative colitis and Crohn’s disease as well.

Parasite therapy is still in the experimental phases, however, and probably has negative effects that outweigh the positive ones. As of now, the FDA has classified the worms as biological products that cannot be sold until proven safe. Only one species, Trichuris suis, has been approved for testing under Investigational New Drug (IND) status.

7Virotherapy

One of the most exciting and promising branches of medicine in recent decades is virotherapy, a biotechnology technique to reprogram viruses to treat disease. In 2005, researchers at UCLA announced that they had turned one of humanity’s deadliest enemies into a cancer-killer when they reprogrammed a modified strain of HIV to hunt down and destroy cancer cells. Around the same time, researchers at the Mayo Clinic in Rochester, Minnesota modified the measles virus to do the same.

The technique is similar to the one used to breed genetically engineered plants, in that a virus is used as a gene-delivery vehicle. It has long been recognized as the most efficient means of gene transfer. This system is used for the production of useful proteins in gene therapy and has great potential for the treatment of immunological disorders such as hepatitis and HIV.

Viruses have been known to have the potential to treat cancer since the 1950s, but the advent of chemotherapy slowed its progress. Today, virotherapy is proving to be extremely effective against tumors without harming the healthy cells around it. Clinical trials of oncolytic virotheraphy have shown low toxicity and promising signs of efficacy. In 2013, a drug called talimogene laherparepvec (TVEC) became the first drug based on a tumor-killing virus to succeed in late-stage testing.

One of the biggest challenges facing researchers is how to deliver the virus where it will do the most good before the body recognizes it as an intruder and mounts a defense. Current research is looking into finding natural tumor-targeting “carriers,” cells that can deliver the virus without either the cell or the virus losing its normal biological functions.

6Using Viruses To Cure Bacterial Infections

Bacteriophages are viruses that specifically attack bacteria. First recognized by Frederick Twort in 1915 and Felix d’Herelle two years later, they have been used to study many aspects of viruses since the 1930s. They are especially common in soil, where many species of bacteria make their home.

Because phages disrupt the metabolism of bacteria and destroy them, it has been long recognized that they could play a role in treating a wide range of bacterial diseases. Because of the innovation of antiobiotics, though, phage therapy was mostly shelved until the rise of antibiotic-resistant bacteria generated a renewed interest in the field.

An individual phage species is generally only effective against a small range of bacteria or even one specific species (its primary host species), which was originally seen as a disadvantage. As we have learned more about the beneficial aspects of our natural flora, though, it has come to be recognized as the advantage that it is. Unlike antibiotics, which tend to kill bacteria indiscriminately, bacteriophages can attack the disease-causing organisms without harming any other bacteria living inside us.

While bacteria can develop resistance to both antibiotics and phages, it only takes a few weeks rather than a few years to develop new strains of phages. Phages can also have an easier time penetrating the body and locating their target, and once the target bacterium is destroyed, they stop reproducing and soon die out.

5Vaccines

Beginning in the 1790s, when Edward Jenner developed the world’s first vaccine against smallpox using a less virulent strain called cowpox to inoculate patients, vaccines have saved countless millions of lives. Since then, several different types of vaccines have been developed. Attenuated or “live” vaccines use live viruses that have been weakened or altered so that they do not cause illness, while inactivated or “killed” vaccines contain dead microorganisms or toxins that are usually used against bacterial infections. Some vaccines—including subunit and conjugate vaccines, as well as recombinant and genetically engineered vaccines—only use a segment of the infectious agent.

When a vaccine is injected, the pathogen goes to work, but there is not enough of it to replicate at the rate it needs to in order to take hold. The body mounts an immune response, killing the pathogen or breaking down the toxin responsible for disease. The body’s immune system now knows how to fight the disease and will “remember” if it comes across it again. In other words, scientists have figured out how to get a pathogen to help its own target defend itself against it. They have even taken the first steps toward developing vaccines for several forms of cancer, with three vaccines approved by the FDA for the hepatitis B virus (which causes liver cancer), human papillomavirus types 16 and 18 (which cause cervical cancers), and metastatic prostate cancer in some men.

Thanks to vaccines, several diseases have been driven to virtual extinction. Smallpox is the most famous example, but polio, though not totally eradicated, comes in at a close second. Several other diseases might be gone by now if vaccines weren’t so hard to come by in the underdeveloped nations that still struggle with them. Things are getting worse instead of better, with diseases coming in from an unexpected source: affluent, educated Westerners who should know better.

Unfortunately, the anti-vaccination movement is making a comeback in regions where these diseases were once under control. Before the introduction of the measles vaccine in 1963, approximately 500,000 people per year were infected in the US, 500 of whom—mostly children—ended up dead. By 1983, there were only 1,497 cases reported, and after a brief resurgence in the ’80s and ’90s, reported cases were down to just 37 in 2004. After the anti-vaccination movement began gaining traction, 118 cases were reported in the US alone in 2011. That number keeps growing, fed by travelers coming in from areas with higher rates and finding less resistance. Whooping cough, once thought to be gone forever in the US, is also on the rise.

4Bacterial Waste Breakdown

Some of the smallest and simplest of creatures on Earth play some of the most important roles in safeguarding all of life. Bacteria have perhaps the most important role of all: breaking down and recycling waste.

The dead remains of animals and plants, along with the excrement of all organisms, contain vital nutrients and stored energy. Without a way to reclaim these nutrients, though, the available sources would be quickly depleted. Luckily, many bacterial species feed upon these energy sources, breaking them down to their smallest molecules and returning them to the soil, where they reenter the food chain.

As helpful as this process already is, humans have found many ways to exploit it for a variety of even more advantages. Bacteria are used in sewage treatment, industrial waste management, and the clean-up of oil spills, leaked pharmaceuticals, and wastewater. They have also been useful in the development of aqua-farming, algae control, and waterless toilets. Researchers and engineers are currently looking into their potential use in the production of environmentally friendly bioplastics, glues, and building materials. They may even be used to break down plastic waste.

3We Would Quickly Die Without Our Gut Bacteria

Poorly understood until recently (and there is still quite a bit of research to be done), the natural bacteria that lives in our guts works with our immune system to drive out pathogens, produce vitamin K, stimulate peristalsis, and perhaps most importantly, digest our food. Without our gut bacteria, we wouldn’t be able to perform any of these functions, and we would quickly die.

The more we learn about beneficial strains of gut bacteria, the more we can incorporate that knowledge into healthy living. After it was determined that certain gut bacteria can play a role in obesity, probiotics became all the rage. Probiotics are the bacteria that reside in fermented foods and are now sold as supplements. Bacteria like some species of bifidobacteria, found in most yogurts, can create a highly acidic environment in which less-beneficial microorganisms cannot survive. Fatty foods and stress can also play a role in the health of our stomach flora, killing beneficial bacteria while favoring the more harmful kind that cause gas, bloating, and “leaky gut syndrome.”

In a huge breakthrough in the study of our gut bacteria and what they do, a team of Chinese and Danish researchers have recently developed a new way to identify these microorganisms using DNA sequence data. They identified over 500 species of benign bacteria and 800 new species of viruses that could live off them, providing hope for new ways to treat diseases associated with them, such as diabetes, obesity, and asthma.

2Skin Bacteria Serve As Our First Line Of Immune System Defense

The moment you emerged from your mother’s womb, you were set upon. They ambushed you in mere moments and colonized every inch of your skin, and they have been with you ever since. They are prokaryotes and other bacteria, and without the evolutionary partnership humans forged with them millions of years ago, you would have been dead soon after being born.

One of the most common skin bacteria is Staphlococcus epidermis, a bug that we now know plays a role in fighting off Leishmania major, the cause of a nasty disease called leishmaniasis that results in skin boils and open sores that don’t heal. The good bug triggers an immune response called IL-1 that the body can’t produce on its own, making Staphlococcus a necessary part of the human body, as vital to our existence as any organ.

Prokaryotes, which also colonize the digestive tract, cover every exterior surface on the skin. Along with the rest of our beneficial skin microbiota, they became a part of us when they started competing against less-benevolent microorganisms for real estate. Along with the immune cells in our skin, they protect us against both pathogenic bacteria and opportunistic fungi that try to invade. This allows our bodies to spend less energy defending our exteriors and focus more on things like fighting viruses and precancerous cells.

While there is still much to learn before we can really use this knowledge in our health regimens, we are already looking to a future that involves the purposeful use of skin bacteria. A start-up based in Massachusetts called AOBiome, for example, has created a body spray made of live cultured chemoautotrophic bacteria called Nitrosomonas. They claim that their spray can “replenish healthy skin bacteria” and even replace showering, as the bacteria live off the ammonia in our sweat.

1Life As We Know It Wouldn’t Be Here Without Cyanobacteria

Cyanobacteria, or blue-green algae, are possibly the oldest still-living species on Earth, with fossils dating back 3.5 billion years. They are unicellular bacteria that grow in colonies, and if it weren’t for them, you wouldn’t be here, and neither would nearly every other form of life.

Cyanobacteria were the world’s first photosynthesizers. They used energy from the sun along with chemicals in primordial oceans and inert nitrogen in the atmosphere to make their food. As a waste product, they generated oxygen, a poison to virtually every other form of life at that time and the cause of early mass extinction events. Over a period of roughly 300 million years, all this oxygen generation helped form the atmosphere as we know it, during the Archaean and Proterozoic eras.

That wasn’t the only way this bacteria kick-started life as we know it. Sometime during the Proterozoic or early Cambrian era, they formed a symbiotic relationship with certain eukaryote cells, making food for the cell in return for a stable environment to call home. These were the first plants, as well as the origin of eukaryotic mitochondria, which is essential for animal life. This truly titanic event is now known as endosymbiosis.

While several forms of cyanobacteria are toxic, a species named Spirulina was an important food source for the Aztecs and eaten regularly by many Asian nations. Today, it is often sold in powder or tablet form as a health food supplement.

Lance LeClaire is a freelance artist and writer. He writes on subjects ranging from science and skepticism to religious history and issues to unexplained mysteries and historical oddities, among other subjects. You can look him up on Facebook.

Nonliving objects and animals are not always safe from litigation. Over the years, people have sued animals and even inanimate objects like puppets. In turn, people have been sued by animals and nonhuman objects.

Obviously, lawsuits of this nature aren’t actually filed by animals or nonliving things but by people or groups. While the following court cases are bizarre, hilarious, or both, they show just how far people will go to get justice.

10 Musician Loses Court Battle Against Puppet

South African musician Steve Hofmeyr holds the rare distinction of having lost a court case to a puppet. The puppet in question is Chester Missing, which is owned by South African ventriloquist and comedian Conrad Koch (pictured above with Chester).

The whole thing began in November 2014, when Hofmeyr blamed black people for apartheid. Koch replied in a series of tweets he posted on his personal Twitter page and Missing’s Twitter page in which he criticized Hofmeyr over his racist statement. One of his messages urged Hofmeyr’s sponsors to cancel their contracts with the musician.

Hofmeyr requested for a protection order against Koch and Missing over what he called threats and harassment. However, he failed to receive the order when a court determined that Koch and Missing had done nothing wrong and could tweet about Hofmeyr. The court also ordered Hofmeyr to pay Koch and Missing’s attorney fees.

Koch quickly returned to making tweets about Hofmeyr, who he called “Racistboy.” The less-than-amused Hofmeyr accused the courts of siding with the comedian and his puppet.^[1]

9 Kansas Sues A Toyota Truck And Loses

In 2018, the state of Kansas lost a lawsuit against a Toyota pickup truck. Sergeant Christopher Ricard of the Geary County Sheriff’s Department stopped the truck over a partially obscured traffic plate. However, he impounded it when Scooby, his police dog, sniffed out 11.9 grams of marijuana hidden inside the vehicle. Sergeant Ricard also found $84,000 in cash.

The state filed to seize the vehicle and money. Considering that it was a civil forfeiture case, the state listed the truck, money, and marijuana as defendants instead of the two men driving it. However, the court determined that the state could not legally seize the truck and money because Sergeant Ricard had illegally extended the stop to allow Scooby to sniff the vehicle.^[2]

8 Police Dog Wins Lawsuit Filed By A Burglar It Bit

On July 6, 2013, a Georgia man named Randall Kevin Jones broke into his ex’s home and stole several items, including her television, camera, and game console. The unnamed ex called the police after spotting Jones leaving her home. Officers from the Gwinnett County Police Department responded to the scene.

The police found Jones and ordered him to surrender. Jones didn’t and started to run. He continued running, even after an officer threatened to send a police dog after him. The officer ultimately unleashed the dog, named Draco. Draco bit Jones, sending him falling into a ravine. Jones required some stitches for his injuries.

Two years later, Jones sued the police department for “excessive use of force.” As defendants, he named at least three officers and the dog, which was listed as “Officer K-9 Draco of the Gwinnett County Police Department in his individual capacity.” Jones claimed Officer K-9 Draco bit him “for what seemed like a lifetime.” He also claimed the officers watched and didn’t try to get Draco off him as this was happening.

Gwinnet County tried to have the lawsuit dismissed, but a federal judge rejected this, so the county appealed. Finally, Judge Robin Rosenbaum of the 11th US Circuit Court of Appeals in Atlanta threw the case out, saying, “We hold that a dog may not be sued individually for negligence since a dog is not a person.” She added that dogs cannot be issued a subpoena, cannot get an attorney, and cannot pay damages if found guilty.^[3]

7 Judge Stops Horse From Suing Its Owner

In 2018, a horse in Oregon sued its owner for neglect. It requested $100,000 in damages. However, a judge threw the case out because horses cannot sue their owners, or anybody for that matter. The horse itself did not file the lawsuit, though. The Animal Legal Defense Fund did on its behalf.

The horse, named Justice, was owned by Gwendolyn Vercher, who had left it outside in the cold. Justice was hungry, thirsty, and underweight by 136 kilograms (300 lb) at the time it was rescued. It also suffered from frostbite. Vercher was charged with neglect of an animal and paid for the horse’s treatment.

However, the Animal Legal Defense Fund filed the lawsuit because Justice could need money for further treatment. The court ruled the horse could not file the lawsuit because otherwise, courts would soon be filled with animals suing their owners. Gwendolyn Vercher said the lawsuit was “outrageous.”^[4]

6 Aborted Fetus Sues Abortion Clinic

In March 2019, Ryan Magers sued the Alabama Women’s Center for Reproductive Alternatives in Huntsville, Alabama, for aborting his unborn child. Also listed as defendants were the company that made the pill used for the abortion, the doctor who did the abortion, and every organization the doctor worked with.

Ryan Magers called the fetus Baby Roe. He claimed his girlfriend aborted Baby Roe in February 2017. She was six weeks pregnant at the time and went ahead with the abortion after he refused. Magers said he filed the lawsuit because he wants the law to protect fathers of unborn children.

For now, the law allows the mother to abort the baby without any consideration from the father. The lawsuit has raised eyebrows among feminists and pro-abortion advocates. The case is currently ongoing.^[5]

5 Monkey Selfie Ends In A Win For Photographer

In 2008, photographer David Slater encountered a troop of crested black macaques while taking pictures at an Indonesian wildlife park. While he concentrated on shooing some curious monkeys, others snuck to his camera, which was on a tripod, and started to click on the shutter.

The monkeys took hundreds of pictures, some of which included Slater. However, the most popular was a selfie taken by a monkey that pressed on the shutter. What followed was a bizarre copyright battle between Slater and the monkey, which was named Naruto.

People for the Ethical Treatment of Animals (PETA) claimed that Naruto owned the copyright to the picture. Slater insisted that he owned the copyright and not Naruto. In 2015, PETA filed a copyright lawsuit on behalf of Naruto. In 2017, PETA agreed to dump the lawsuit on the condition that Slater gave them 25 percent of the royalties he received from the images.

However, in 2018, a court stopped PETA from settling the lawsuit because it wanted to pass judgment that would allow judges to decide over similar incidents in the future. The court ruled that animals cannot file or own copyrights. This effectively gave copyright ownership to Slater.^[6]

4 Wheelchair Thief Sues Police Dog

On April 23, 2015, 55-year-old Stanley McQuery broke into the Hillcrest, San Diego, home of 79-year-old William Ballard. He attacked Ballard and stole his phone and electric wheelchair. He also demanded money. The police were called in.

Officers found McQuery in the neighborhood. For some reason, his getaway vehicle was Ballard’s wheelchair, which traveled at a pitiable 3.2 kilometers per hour (2 mph). The police sent a dog after McQuery after he refused orders to stop. McQuery was ultimately sentenced to 16 years in prison because he already had three felony convictions.

In 2016, McQuery sued the police dog for “excessive force, assault and battery” while in prison. He demanded $7 million in compensation. He claimed he was already on the ground at the time the officer set the dog on him. He added that the officer told the dog, “Eat him up, eat him up.”

McQuery later claimed he made a mistake by naming the dog as a defendant. He said he loved dogs and never planned to sue a dog. However, this does not explain the fact that he listed the dog as a defendant twice.^[7]

3 Monkey Gets Charged With Assault For Attacking Woman

On November 29, 1877, The New York Times reported that one Ms. Mary Shea lost a lawsuit against Jimmy Dillio, a monkey owned by one Mr. Casslo Dillio. Trouble began for Jimmy when Mr. Dillio took him to Ms. Shea’s shop. Shea offered Jimmy a piece of candy, which he accepted while chattering in appreciation.

However, Jimmy turned violent and bit Ms. Shea’s finger when she playfully attempted to retrieve the candy. Mrs. Shea got Mr. Dillio and Jimmy arrested and taken to court. Judge Flammer threw the case out, saying the that court could not charge monkeys. Jimmy reportedly exhibited some gentlemanly behavior by doffing his hat after Judge Flammer delivered the decision.^[8]

2 Woman Attempts To Get Monkeys Charged With Sexual Assault

In 2015, 23-year-old Melissa Hart tried getting a pair of monkeys arrested and charged with sexual assault while he was visiting Gibraltar. She was watching the Barbary macaques when two of them attacked her without warning.

The monkeys scratched her with their paws, pulled at her clothes and hair, and removed her bikini top. She screamed for help during the attack, but nearby tourists just laughed. She was saved when a warden chased the monkeys away.

A startled, embarrassed, and angry Ms. Hart reported the incident to the police and tried to file charges against the monkeys. The officers turned down her request because monkeys are wild animals and cannot be charged. One officer even asked her if she could identify the monkeys in a police lineup.^[9]

1 Man Sues Police Dog After He Was Bitten

In 2018, 66-year-old Joseph Carr of Oregon sued a police dog named Rolo and its handler, Deputy Jason Bernards of the Marion County Sheriff’s Office, because Rolo bit him. Rolo bit Carr on September 18, 2016, as Carr attended the opening of a store.

Carr met Deputy Bernards and Rolo standing at the entrance of the store. Bernards told Rolo to “say hi,” which Carr took as an invitation to pet the dog. However, Rolo bit Carr in the abdomen when Carr touched the canine’s ear and head. Carr sued for $50,000 in damages.

Deputy Bernards claimed that Carr was bitten because he wrapped his hands around the dog’s snout. However, Carr’s attorney, Brian Hefner, noted that surveillance footage shows that Carr only touched the dog’s head and ear. Carr said the bite scar constantly reminds him of the “horrific and unnecessary event.”^[10]

Based on his expertise on ancient documents and biblical genealogies, the Irish Archbishop James Ussher (1581–1656) estimated that our planet was created in the morning of October 23, 4004 BC. Our understanding of world chronology has come a long way since Ussher’s times, thanks to many of the clever dating methods we have developed.

10Linguistic Dating

As time goes by, two geographically isolated communities that speak the same language will display differences in the way they talk. After a few generations, language change becomes more significant. After thousands of years, we’re most likely faced with two related but totally independent languages.

Linguistics can date text on documents, pottery, building walls, and numerous other surfaces. Many important ancient texts have been dated on the basis of linguistic comparison, such as the Zoroastrian Avesta, which is believed to have been written somewhere between 1200–1500 BC based on linguistic similarities with the Indian Vedas.

9Tree-Ring Dating (Dendrochronology)

Most tree species produce new wood each year, resulting in rings of growth that can be easily detected in a cross-section of its trunk. By matching ring sequences from living trees of different ages, it is possible to create a long tree-ring sequence for hundreds, sometimes even thousands of years back in time.

In Alchester, north of Oxford in England, the remains of a Roman fort was uncovered by archaeologists. Thanks to the soil conditions, two large timbers that supported the gate structure survived. Dendrochronological analysis established that both trees were cut between October in the year 44 and March in the year 45, a date consistent with historical data, since the Roman conquest of Britain dates to AD 43.

8Seriation Dating

Many of us can mentally arrange most human creations in a chronological sequence. Archaeologists can do the same with past artifacts. Creations coming from a particular place and time display a distinctive style.

Pottery styles seriation is the foundation of many chronological sequences. Most human cultures later than 8000 BC possess a distinctive ceramic style. In Greece, for example, the Black Figure pottery style (black figures on red background) was dominant from 625 BC until 530 BC, when it became replaced by the Red Figure pottery (red figures on black background). A fragment of Greek Black Figure pottery found in an archaeological context may indicate that the context is no earlier than 625-530 BC.

7Thermoluminescence

Thermoluminescence (TL) can be applied to crystalline materials buried in the ground that have been previously exposed to fire, such as pottery. During a TL test, pottery is heated up, releasing trapped energy in the form of light. This light is measured, revealing the amount of time since the formation of the crystal structure.

From the moment the vessel was fired until the moment it is analyzed, the vessel had been absorbing radiation from the nearby environment. This energy is trapped and accumulated in the pottery’s mineral structure. For an accurate reading, archaeologists have to measure the radiation level at the exact place where the sample was found in the soil. This radiation level is not representative of the radiation level to which the sample was exposed prior to being buried, which is why TL dating has a precision of plus or minus 10 percent and it is often cross referenced with other dating methods.

6Electron Spin Resonance

Like TL, Electron Spin Resonance (ESR) also measures trapped energy. Unlike TL, the ESR test does not heat up the sample, which makes it suitable for materials that decompose when exposed to high temperatures.

ESR is typically used to date tooth samples. Once buried, tooth enamel begins to accumulate energy derived from background radiation. The precision of ESR dating is plus or minus 10–20 percent. Although this figure might seem inaccurate, ESR can provide valuable results for the study of early humans, where we often deal with figures of hundreds of thousands of years.

5Chronologies And Calendars

The dating of the most recent human past used to be largely based on historical chronologies, records and calendars left behind by past civilizations. But ancient calendars tend to run based on a local timekeeping system, normally aligned to a succession of local kings or ruling dynasties. The only way to make these calendars meaningful is to link them with our own calendar.

When two or more of these societies become in touch, we can sometimes find the same events recorded in two independent timekeeping systems, which allows us to align these different calendars. Alexander’s conquest of Egypt in 332 BC, for example, aligns Egyptian and Greek timekeeping systems.

4Cross-Dating

Before modern dating scientific techniques were developed, cross-dating was applied when artifacts from a known sequence coming from a historically dated region was found in areas for which we did not have any reliable chronological information.

While excavating the Palace of Knossos in the Greek island of Crete, several imported Egyptians items dated to 1500 BC were retrieved. This, combined with several examples of Cretan pottery found in Egyptian archaeological contexts of around 1900 BC, allowed archaeologists to extend Egyptian chronology into Crete.

3Radiocarbon Dating

Although the atom of carbon normally has six neutrons in its nucleus (carbon-12), we are surrounded by a small quantity of carbon containing eight neutrons (carbon-14). Carbon-14 is a high energy, unstable atom and tends to decay. The amount of carbon-14 in a given sample will be reduced to half (this is known as half-life) approximately every 5,700 years.

When an organism dies, the exchange of energy and matter stops, and it can no longer incorporate carbon-14 in its tissue. As time goes by, the amount of carbon-14 is reduced, and because we know the rate at which this loss takes place, we can estimate the time elapsed based on the reading of carbon-14 concentration.

This technique can be applied to almost any organic material (human remains, charcoal, plant remains, etc.). One limitation is the age of the sample: Material older than 70,000 years old do not have enough carbon-14 concentration to allow a precise reading. The same happens with samples that are too recent because the concentration of carbon-14 might be too high.

2Potassium-Argon Dating

Radiocarbon dating applied to East African hominin fossils did not produce any results, which suggested the remains of the earliest members of our human evolutionary tree were older than 70,000 years old. Archaeologists sought the help of geologists and a dating method known as Potassium-Argon dating.

Potassium-40 is a radioactive isotope that decays into argon-40, an inert gas. When new volcanic rock is formed, its content of argon-40 is emptied as the gas escapes. Its half-life is about 1.3 billion years. A reading of the relative number of potassium-40 and argon-40 atoms in a volcanic rock sample can be translated into the amount of time elapsed since the formation of the rock.

Many important archaeological sites where early hominins were found are located in areas abundant in volcanic rock. Sometimes, hominin remains are found within a geological layer that can be dated using the potassium-argon technique and some other times they are sandwiched between layers of volcanic rock that can be also dated with this dating method.

1Stratigraphy

As archaeologists conduct an excavation, they expose and study the stratification of the soil (the multiple layers of soil underneath the surface). If no evidence of either human or natural disturbance is found, it is assumed that the underlying layers were deposited prior to the overlying layers.

Stratification only tells us a relative chronological sequence from the earliest bottom layers to the newest archaeological deposits on the top. Some of the material we retrieve from these layers will be suitable for absolute dating. We may find organic material (e.g. bones) suitable for radiocarbon dating or maybe pottery fragments suitable for a Thermoluminescence test. In those cases, we can establish a date for all other items found in the same layer.

When our distant ancestors left the trees to walk the savannas, physical changes occurred that can still be seen today. Some are vestigial and no longer needed, while others endure as efficiently as always.

In fact, modern humans can thank several ancient perks for their survival, including laughter and eyebrows. Human evolution is far from over. From changing female voices to genes that ruin drinking games, things are set to get more interesting.

10 Nails Are Really Ancient

Primates sprouted nails as far back as 58 million years ago. This provided the tree-dwelling creatures with several benefits. The main job was to better equip them to navigate trees, to which they were basically confined.

Nails strengthened the fingers, allowing for a better grip, and protected the nerve endings that permitted the fingertips to feel the world. They also brought food perks. Compared to other tree animals, primates excel at harvesting fruit at the end of branches—a tricky feat that requires good maneuvering and a great grip on the narrowing foliage.^[1]

Humans no longer nest in trees. At one point, an ancestor decided that the land was a better deal. As the lineage evolved, people ended up in caves and eventually penthouses.

Through all the physical changes, including a radical habitat shift and thousands of years, humans retained their claws. The “tree dexterity” of nails simply switched over into productive toolmaking and the infinite tasks that human hands can do today.

9 The Purpose Of Laughter

At first, laughter seems straightforward. Humans laugh when they find something funny (or pretend to). Looking back, it would appear that lives depended on how social and amiable one seemed. Nobody would have invited the caveman with the killer stare and argumentative nature. Nope. In winter, they probably left him outside the cave and watched him expire.

Studies have shown that laughter is a powerful social glue. Back in the day, the habit probably evolved as a verbal way to cement alliances and negate violence. While aggression was always a primary human trait, one might be less inclined to strangle the guy who laughed at your jokes during the last meeting at Stonehenge.

Interestingly, while fake laughter appears to lower the same barriers as a genuine cackle, it might not fool outsiders. During a 2016 study, volunteers from 24 different societies accurately detected pairs of strangers or two friends just by listening to one of them laugh.^[2]

8 Unexpected Female Dating Voice

In 2018, researchers herded 30 speed daters together. The women stayed at the tables, while the guys rotated every six minutes. Each had to mark a card showing whether they fancied the other person or not.

When researchers listened to the recorded conversations afterward, it became clear that both genders lowered their tones with somebody they liked. This clashed with previous studies showing that men were attracted to women with higher voices because they sounded younger and more feminine.

The surprising mutual drop in tone has not been solved, although researchers agree that it could be an evolutionary tool to snag a mate. Some suggest that the women used a more dominant pitch in the competitive environment of speed dating.

However, others feel that a quieter way of talking is a lot more intimate. When dating happens in a room full of people, a woman might drop her voice merely for privacy.

Interestingly, voice recordings of women in 1945 compared to ones taken during the 1990s showed that the female tone has lowered. This could be because women are trying to communicate maturity, competence, and dominance in a more equal opportunity world.^[3]

7 The Human Fur Mystery

Compared to other animals, humans are fairly bald. Fur kept our earliest ancestors warm, protected their skin, and provided camouflage. Something pressured evolution to erase it.

The prevailing theory suggests that it was the ancestral decision to abandon trees for living in the open savannas. This new environment would have been a lot hotter. A body covered in hair would have made living and hunting in the sun’s heat impossible.^[4]

It is also thought that human sweat glands boomed when hair turned sparse. In fact, modern humans are the sweatiest primates on the planet. Around five million glands produce up to 12 liters (3 gal) of sweat daily. This amount would have kept humans cool in the savannas but only if they were hairless.

The neat-sounding theory has many holes. It cannot be proven that hair loss and the sweat gland explosion occurred at the same time. Researchers are also uncertain how these individuals dealt with excessively cold temperatures, what genes were involved, or even when human fur vanished.

6 Slow Big Toe

In 2018, a study identified the big toe as one of the last foot bones to evolve after humans crossed over from tree-swinging to ground-dwelling ancestors. To walk upright took a major overhaul of the feet. The big toe was instrumental in this change because it allows traction during walking.

Despite its importance, the largest toe stuck to its primate origins the longest. This was probably because it was the most difficult to change. In the beginning, the toe was almost like a finger, grasping branches and working as a tool.

This highly useful feature had to turn rigid to ensure effective locomotion on two legs. For this reason, the change occurred gradually over millions of years.^[5]

The study’s findings were surprising in a way. The big toe remained opposable for much longer than thought, proving that it did not truly interfere with the ability to walk efficiently.

5 Why Men Have Nipples

Male mammals cannot feed their young, and yet they have the tools to nurse. Some men even lactate, although this is usually due to a hormonal problem. Guy nipples are not an evolutionary quirk. They are the result of a biological process that prevented evolution from erasing a useless trait.

A mammal embryo has the potential to become either sex. When the time comes to swing one way or the other, the embryo’s chromosome set decides the gender. If the male XY set is present, a gene called SRY activates and ushers in everything the embryo needs to develop into a boy.

However, there is another process that happens before the male genetic switch can flip. In mammals, the mammary glands begin to develop extremely early and these glands do not care for any old chromosome set. They set the stage for breast tissue and nipples, and there is nothing that SRY or evolution can do about it.^[6]

4 A Useless Tendon

There are times when evolution cannot be bothered to sweep up the leftovers. One of the most useless things that nature left in the human body is the palmaris longus tendon. It is quite a prominent feature in the wrist. Most people can see it when they touch their thumb and pinkie together and slightly tilt the hand toward themselves.

A raised line will appear in the middle of the wrist. If not, they are among the 10–15 percent of people who were born without it. The tendon connects to the palmaris longus muscle but does not make it stronger. The only time it serves a purpose is when surgeons remove and use it elsewhere in the body during plastic and reconstructive surgery.^[7]

It remains unclear why humans have this useless tendon. A tentative guess considers it a relic from a time when the forearms were used as much as the legs to move around. Why? Modern mammals with the most developed palmaris longus tendon do just that—including monkeys and lemurs.

3 Eyebrows Saved The Species

Eyebrows serve one obvious purpose today. They act as a protective barrier for the eyes by stopping rolling fluids and debris. But in 2018, researchers made a surprising case: Without eyebrows, humans might have gone extinct like the Neanderthals.

Sounds extreme, but the proof could be in the brow bone. Neanderthals and other ancient hominids had prominent bony ridges above the eyes, very much like some primates today. Studies showed that this ridge, which is absent in humans, had no real purpose other than to look fierce.

Looking fierce in a primitive world is not always the wisest move. Tempers flare, and clubs start swinging. Worse, this ridge prevented Neanderthals from maneuvering their eyebrows to look friendlier. That was the difference that might have saved the human race. Our eyebrows convey subtle signals of compassion, sympathy, and friendliness.^[8]

The fossil record backs up this wacky-sounding hypothesis. The human brow ridge started to recede during a time when important social connections began between distant groups. Being able to eyebrow-signal one’s friendliness would have gained more allies than enemies—and thus more power.

2 The Returning Bone

There is something strange going on with the human kneecap. It was once accompanied by a tiny bone called the fabella. It did the same job as a modern kneecap for Old World monkeys about a zillion years ago. As humans evolved, it shrunk and eventually got lost. However, it just took a few knee operations and scans to notice that the fabella was still present in some people.

In 2019, researchers threw out a wide net. They reviewed medical records from 27 countries that involved more than 21,000 knees. The results were clear. The tiny bone was coming back.

The records spanned almost a century, and the earliest showed that around 17.9 percent of the population had it in 1875. Only 11.2 percent had it in 1918. However, by 2018, around 39 percent of people were estimated to possess the returning relic.

Evolution is not always positive. Those with a fabella are more likely to suffer inflammation, osteoarthritis, and a variety of knee problems. The boomerang act remains unsolved, but it could have something to do with bigger, better-nourished modern humans putting more pressure on the knee.^[9]

1 The Hangover Genes

One of the weirdest ways humans are still evolving concerns the alcohol dehydrogenase (ADH) gene cluster. In 2018, researchers found signs that the region was changing—which is not good news for those who like their liquor.

Normally, when a person guzzles a beer or 50, the body breaks down the alcohol into toxic acetaldehyde. When this stuff accumulates, the drinker no longer feels so jolly. The face flushes, and the person experiences nausea and a rapid heartbeat. Typically, acetaldehyde is quickly metabolized into a less bothersome acetate that is easily eliminated from the body.

Some individuals with East Asian and West African ancestry showed an evolved ADH cluster, which makes drinking uncomfortable really quickly. This adaptation makes it difficult to process alcohol, so such people are struck down faster with super hangovers. It is not clear how quickly the adaptation is spreading to other populations or whether the genes changed in an attempt to shield humans from drunkenness.^[10]

Today’s pets are often taken care of with the same level of involvement that people once reserved for their children or grandchildren. We fuss over diet, activity, training, and health care for our pets to make sure that they have the best lives possible. This is the movement that has led to many referring to themselves as pet parents,^[1] rather than pet owners. Experts suggest that the root of this change is twofold. Young adults are having fewer children, while aging baby boomers are becoming empty-nesters. Both groups are filling the void where children would be with new pets.

But the drive for better pet health care has brought an issue to light that was previously unknown to the population at large: Pets need mental health care. Our animals, be they mammal or otherwise, can suffer from myriad mental illnesses and disorders just like we do. Pets also take medication, have therapy, and recover just like we do. As more of us are realizing how important it is to treat our pets’ mental health, it is more important than ever to ask what is causing the distress in the first place. Between our hectic lives and loud modern environment, we may be more responsible than we’d like to admit.

10 Pica

Most dog owners have a hilarious story about how their dog chewed up something important, like homework, or infeasible, like a chunk of drywall, and many cat owners know that it’s impossible for their feline companion to resist a nibble of any plastic bag left out for even one second. What people don’t tend to realize is the extreme cost of this behavior, in both actual money and danger to pets. When an animal eats something that isn’t food, it’s called pica. In cats, it is sometimes known as wool-sucking behavior due to a habit that Oriental breeds and too-early-weaned cats have of nursing on anything soft and fuzzy, usually wool. In dogs, it’s often known as eating your homework.

Regardless of the terminology, pica can range from a minor inconvenience to a life-threatening disorder. Despite the wild tales of garbage-eating dogs and yarn-slurping cats, a small mammal’s digestive tract isn’t that ironclad. Cats especially suffer from obstructions when they eat random objects off of the floor, and the procedures to fix it can set owners back several thousand dollars. And the surgery to remove a hairpin or slipper from a treasured pet’s intestines won’t fix the behavior, so owners might find themselves right back at the emergency vet’s as soon as the pet has healed if they don’t seek mental health treatment. When pica is caused by a nutritional deficiency or dental problem, it is fairly easy to treat. However, pica is often due to boredom or separation anxiety. When this is the case, it can be harder to treat, but more time and play can sometimes solve it. But some pets eat nonfood items compulsively,^[2] and that can often only be treated by locking the items away and cleaning a little more obsessively.

9 Binge Eating

It’s difficult to know if our animal companions suffer from eating disorders as we do, since we can’t easily confirm the mental and emotional drive behind a pet’s eating habits. What we can know is that some animals eat rarely, such as when a pig suffers from thin sow syndrome, and some eat to excess, such as dogs that can eat 16 percent of their body weight per feeding if allowed.^[3] Cats and dogs can suffer from overeating and binge eating, but the problem extends to even more exotic animals. Binge eating in humans is sometimes studied by attempting to recreate the disordered behaviors in rats and mice, with reasonable success. Most animals want to eat and will stuff themselves if allowed. Veterinarians warn about the dangers of overeating in virtually all small pets, including birds, reptiles, amphibians, rodents, rabbits, and hedgehogs.

But many people, professionals and laymen alike, note that you rarely see an overweight animal in the wild. Animals without enough excitement in their lives will often fall back on food for their entertainment, and food-seeking behavior is a necessary adaptation for animals that would have to catch their own meals in the wild. Cats left to their own devices, like those kept on farms, tend to keep themselves busy chasing prey. So treatment for binge eating in pets tends to focus on more exercise, more entertainment, and less food. The last item tends to be the hardest for many owners. When our cute dogs and cats beg for food, it’s hard to deny them. We don’t call them puppy dog eyes for nothing. But professionals suggest diverting a pet’s attention to some kind of activity instead. A bored pet will often literally jump at the chance to play and forget all about the treats.

8 Trichotillomania

Hairballs are a common problem for those who keep cats. Grooming is important for felines, and a lot of fur can end up swallowed in the process. Hairballs are normal, though, and cats that produce them are rarely in any danger. It’s only when a pet starts to groom so obsessively that their fur becomes patchy and their skin irritated that owners should worry. Trichotillomania, “trich” for short, is a compulsive disorder that causes sufferers to pluck their hair uncontrollably and for non-cosmetic reasons. In animals, this is often called over-grooming, and it is most often a response to stress. For most mammals, dogs and cats included, grooming behaviors release calming endorphins.^[4] Many a human has a bath bomb collection for the same reason. Obsessive grooming, like trich, is a calming habit that becomes too much. In some extreme cases, a pet may leave themselves virtually bald by over-grooming.

In cats and dogs, licking tends to happen in places that are easily reached. This can be paws but is more often a place that is harder to spot, like the thighs and underbelly. In rodents, trich is known as barbering and results in bald patches, nibbled whiskers, and irritation both physical and mental. Dominant mice will groom submissive mice normally, but the submissive mice get the worst of it when the dominant mouse experiences extreme stress. Often, a group of healthy mice will be shipped somewhere and arrive with all but one or two balding and annoyed. Even hairless creatures, like birds, exhibit feather-destructive behaviors. No one knows why a bird starts to pluck itself, if the behavior exists in the wild, or how to fix it. Even well-enriched birds in an ideal environment will develop trich. This is true of humans as well and may hint at genetic origins. For many, helping with trich is a matter of adjusting the environment until the behavior calms down and hoping that it goes away and stays away.

7 Autism

Autism spectrum disorder is not so often considered an illness anymore. Many consider autism to be a perfectly normal facet of human psychology that is misconstrued to be a disorder, while others contend that the difficulties faced by autistic individuals justify the disorder classification. Outside of this hotly contested point, the question that some animal researchers have is whether or not dogs can be said to have autism. When a dog whips around in circles to chase its tail, it’s adorable. However, it’s also a repetitive behavior that resembles the spinning and other repetitive motions that autistic people exhibit. And not all dogs chase their tails. It’s linked to certain breeds and certain genetic lines, particularly Bull Terriers, which are the go-to breed for exploring possible canine autism.^[5]

This breed is known for its quirky behaviors, including obsessive tail-chasing, chewing, and playing. They also have more breed-specific oddities. “Trancing” occurs when the dogs come to a slow-motion stop in the midst of play to stare off into the middle distance. “Ghost-walking” or “moon-walking” is a sort of gliding motion that they take on when sneaking under shrubbery. And Bull Terrier lovers affectionately refer to a particular gait where the butt is tucked under and the dog wildly runs as “Hucklebutting.” Obsessive tail-chasing seems to be the best marker to follow when determining whether or not a Bull Terrier may exhibit autism-like traits. Tail-chasing disproportionately affects males and is correlated with partial seizures, skin conditions, gastrointestinal issues, and fixations. As far as behavior goes, this subset tends to be less social with other dogs and humans as well.

Nicholas Dodman, a veterinary behaviorist at Tufts University, has studied children with autism alongside Bull Terriers to determine whether or not this theory holds water. Two blood chemicals associated with autism, neurotensin and corticotropin-releasing hormone, were tested between children with autism, Bull Terriers, and a control group. The chemicals were higher in both the children and dogs, lending a little more weight to the study of autism in animals. Researchers like Dodman are hoping that research into canine autism can help give insight into human autism.

6 Depression

Unlike many other disorders, depression is fairly well-documented in nonhuman animals. Those that have been scientifically shown to suffer depression are nonhuman primates and rats, most likely because these are common test subjects and are observed very regularly. However, many zoo animals show signs of the illness, like lethargy, compulsive behaviors, disrupted appetite, lack of sexual interest, and self-harm. And many veterinarians will prescribe antidepressant medication for dogs that show similar symptoms. But vets are also clear that we don’t really know if our animal companions suffer from depression in the same ways that we do, because we can’t ask them to describe their experience. We can only observe our pets and make our best guesses.

The first course of action for a depressed pet is to eliminate the possibility of an underlying medical condition.^[6] Both depression and physical illnesses can cause unhappiness, withdrawal from social interaction, and other odd behaviors. Once a physical problem is ruled out, a vet may prescribe medication for a cat or dog depending on the duration and severity of the depression. Professionals will also make inquiries about the pet’s environment and events that have recently taken place. The death of a companion is a common cause of depression in dogs. But it is unusual for a dog’s depression to be chronic, so most treatment is focused on alleviating the harmful symptoms until the issue resolves itself. For cats, depression isn’t so much of a concern. Vets agree that cats are much less likely to suffer depression than dogs. A cat’s difficulties in life are much more likely to result in anxiety.

5 Anxiety

Stress is a normal reaction for animals when their environment becomes dangerous. When food is uncertain, noise levels are too high to hear predators approaching, or one finds themselves trapped in a small box, stress tells animals that it’s time to act. These responses can be triggered in a pet’s domestic life. Vacuums, strangers, and missing human companions can make a pet stressed, but some pets will experience far more stress than others. Ultimately, it is the habit of anticipating fear and stress that makes anxiety, which is suspected to be the underlying cause of many mental health concerns in animals. For cats, that means trembling, hiding, aggression, loud vocalizations, and an aversion to the litter box.^[7] For dogs, it’s usually about the same. In birds, signs can include self-mutilation and stress bars appearing near the base of feathers. In rodents, handling anxiety is a well-documented problem that often skews scientific study.

As with many pet mental disorders, a vet will first rule out physical concerns. This prevents unnecessary treatments and, more importantly, catches anything serious early. Once that’s ruled out, a vet will work with the family to find out what is causing the stress and anxiety. If the stressful situation can be avoided entirely, that could solve the problem. That isn’t always possible. Vacuums have to run, vets have to be visited, and various things will happen outside the window that will upset and fascinate our pets. The next option is to train and condition the pet to be less fearful. This can involve training the pet to stay focused on their human, incremental exposure therapy, or using other methods to calm the pet. When a pet can remain calm during a stressful event, they can start to break the negative association. Sometimes, medication will be used to achieve that calm, but other products, like a thundershirt (a vest that makes the animal feel more secure), can help to break the cycle of anxiety.

4 Sleep Disorders

Both cats and dogs can suffer from a few different sleep disorders. Narcolepsy can cause pets to collapse into a deep sleep, sleep apnea can destroy sleep quality and collapse airways, and REM behavior disorder can cause dogs to get up and run into walls in their sleep. Some fear that their pet suffers from night terrors, but this is most often a misidentified seizure disorder. Insomnia is by far the more debatable sleep disorder in pets than in humans. Cat owners often describe their cats as insomniacs, but this often stems from a misunderstanding of the cat sleep cycle. Cats are crepuscular, meaning that they are most active around sunset and sunrise. Some owners think that their cat should sleep at night and become concerned when that doesn’t happen, while others think that cats are nocturnal and fret over how much nighttime sleep their feline gets. In dogs, insomnia is rare but does occur. Both cats and dogs can benefit from getting more activity during the day and can be trained to calm down near bedtime. Insomnia is a bigger concern in older pets. If cognitive dysfunction affects an aging cat or dog, insomnia often develops, along with several other mental illnesses like depression and anxiety.

For smaller and more exotic pets, the issue is more complex. Research suggests that sleep tied to light cycles, or circadian sleep, may go back in evolution to fish. When zebrafish were altered to cause narcolepsy, the fish developed nighttime insomnia instead. But the fish only engaged in napping when left in a dark room, suggesting that light exposure affects them strongly. It’s thought that true sleep, which cycles through different levels of brain activity throughout, developed in a common ancestor of reptiles, birds, and mammals that lived 300 million years ago.

Treatment of sleep disorders varies.^[8] Narcolepsy is incurable but manageable. Sleep apnea may require surgery to fix an obstructed airway. Melatonin, acupuncture, and herbal medicines can help with insomnia, but vets will also sometimes prescribe a special diet high in omega-3 fatty acids and antioxidants. In older pets experiencing cognitive dysfunction, that will be treated in the hopes that other issues clear up along the way.

3 Alzheimer’s Disease

While aging can contribute to many other mental illnesses in pets, it can also bring its own specific concerns. Many pet owners will shrug off their companion’s strange behavior, especially as the animal ages, but sudden changes are a serious matter for older pets. It is normal for pets to slow down as they age and lose their sight or hearing. However, their mental capacity should not decline significantly. This can signal that a pet has cognitive dysfunction syndrome, or CDS, the sort of dementia that is particular to cats and dogs and which closely resembles Alzheimer’s in humans.^[9] Pets with this disorder may forget well-established routines, wander aimlessly and restlessly, become aggressive, or get lost easily. They may also forget people that they have lived with their whole lives and react as if those people are strangers.

What is extraordinary about CDS in cats and dogs is that Alzheimer’s-like diseases don’t appear in many animals. Scientists have long been frustrated by the lack of dementia symptoms in rodents and nonhuman primates. Researchers think this suggests that cognitive impairment may be a side effect of the long lives that our pets now experience. Since our animals enjoy better diets, environments, and medical care, they often live as long as they possibly can. Wild animals tend to be picked off quickly when they experience even minor impairments, such as bad hips or teeth. Any wild primate or rodent that did develop dementia would likely die before anyone took notice. One animal that may suffer dementia symptoms along with cats, dogs, and humans is the horse. Later in life, many horses begin to show the signs, but the MRI that could confirm the condition is expensive, and the anesthesia is dangerous to the horse. Many owners don’t want to go through the expense or risk their beloved horse for research purposes.

Treatment for CDS is focused on slowing the progression with diet and exercise. The supplement SAM-e is often prescribed in humans and animals for cognitive degeneration. It is also prescribed for managing pain, healing spinal cord damage, and to treat osteoporosis. Specially formulated diets that include antioxidants and fatty acids can help pets’ bodies fight off the onset. Similar to humans with early-stage Alzheimer’s, vets suggest that pets suffering from CDS get more mental stimulation and exercise. Whatever the treatment plan may be, it needs to be started early. Some pets will have a rapid onset and will lose much of their memory and function before their owners take notice of the problem.

2 OCD

Obsessive-compulsive disorder tends to be oversimplified in casual conversation. If someone likes things a certain way or cleans a little more than usual, people may label them as “OCD.” Cats also get this reputation for their meticulous bathing habits and finicky preferences. But, just as with people, OCD has much more to do with obsessions and compulsions than with quirkiness. In fact, OCD sometimes expresses itself in a way that makes things less neat and clean. For cats, it often leads to illnesses like trich and pica that are anything but tidy. OCD cats may also engage in loud, repetitive yowling and pacing. They may also rip apart our furniture and stop using their litter box. In dogs, the symptoms are much the same. But, like autism, some dog breeds are more prone to OCD than others. About 28 percent of US Dobermans have the disorder, and a study of their brains has shown similarities with brain scans of humans with OCD.^[10]

Treatment for OCD pets is like most mental health treatment. Vets first rule out other causes and then look closely at the behavior and environment it takes place in. OCD involves training humans as much as it does pets. Many owners will attempt to punish the behaviors, which increases the anxiety at the heart of the disorder and may make things worse. A hostile or unpredictable environment will make a pet more anxious. Confinement is a bad idea as well, since pets with OCD often get worked up when they feel trapped. Paradoxically, attention, treats, and play during an episode will also reinforce the behavior. The best approach is to remain calm, remove anything harmful to the pet, and observe covertly. Owners can often find the best way to help their pet just by watching and taking in the episode without reacting. Careful observation can often help people realize what it is that their pet needs to feel more comfortable and calm.

1 PTSD

Service pets are often recommended for people who suffer from PTSD and can be a huge help in their recovery. PTSD, or post-traumatic stress disorder, is a response to a traumatic event in which serious harm was threatened or sustained by an individual. It features panic attacks, flashbacks, and other anxiety symptoms. Some people will go through terrible events and emerge unscathed, while others may go through a relatively minor event and come out with PTSD. There’s nothing unusual about this; it simply has to do with the way each individual processes stress. For pets, it is the same. Cats and dogs can develop PTSD from being abandoned at a shelter or during massive natural disasters. Dogs in particular often get it after military or police service.^[11] These dogs are often introduced to stimuli like gunfire and explosions in a controlled training environment, but the difference between training and reality is vast.

PTSD or similar disorders appear throughout the animal kingdom. Abandoned birds, especially parrots, show signs of the disorder. They pace, repeat haunting phrases, and call for missing family members. These birds are sometimes employed to give company and comfort to people who suffer PTSD. Rats have been exposed to traumatic events in laboratories to produce PTSD-like symptoms so that the disorder can be studied more thoroughly. Those with PTSD-like symptoms perform tasks more poorly than their more resilient or less traumatized peers, even after time has passed since the original event.

To help pets with PTSD, it is necessary to seek the help of a professional. Therapy is invaluable for helping pets learn to process their trauma and training them to respond to it appropriately. A tricyclic anti-depressant is often prescribed to ease distress, but it is also critical to give pets with PTSD a safe, secluded retreat where they can rest without worry. Play and attention are good passive therapies, but only if owners can keep calm and patient with their pet. Any anger or scolding can cause massive setbacks. However, with patience and therapy, pets tend to recover from PTSD well.

Renee is an Atlanta-based graphic designer and writer.