When you hear the phrase 10 worms used by people, you might picture garden soil or fishing gear. In reality, worms have slithered into far‑more unexpected corners of our lives – from high‑tech silk to weight‑loss curiosities. Below, we crawl through each of the ten most fascinating species and reveal how they help (or sometimes haunt) humanity.

10 Worms Used By Humans: An Overview

10 Night Crawlers

The world of beauty products has long borrowed from nature, and one of the most unusual ingredients comes from earthworm droppings. After these wrigglers tunnel through soil, they excrete nutrient‑rich castings that are harvested and blended into anti‑aging creams. Manufacturers claim these worm‑derived castings deliver copper peptides, auxins, kinetins, humates and cytokinins, which together hydrate skin, firm tissue, stimulate collagen production and encourage healthy cell growth.

Night crawlers are among the most ubiquitous earthworms, thriving in gardens across the globe. Two main varieties dominate the market: the European night crawler, which tops out at about 7.6 cm (3 in), and the larger Canadian night crawler, which can reach a whopping 36 cm (14 in). Both are prized for multiple purposes, from fishing bait to composting to feeding pet reptiles.

European night crawlers are often employed as live bait, compost enhancers, and even as a food source for turtles and lizards. Their Canadian cousins are especially valued by anglers because they stay alive for up to five minutes underwater, their wriggling motions enticing even the wariest fish.

Believe it or not, the castings left behind by night crawlers are a commodity sold online. Suppliers collect, screen, and quality‑check the feces before storing them in moist, aerated conditions for shipment to cosmetic labs worldwide.

In addition to their skin‑care benefits, the worm castings are said to contain a cocktail of growth‑promoting compounds. Users of these products report smoother, more supple skin and an overall boost in the skin’s ability to repair itself.

9 Bloodworms

Bloodworms, named for their vivid scarlet hue, dwell at the bottom of freshwater and marine environments. Their bright color and high protein content make them a favorite snack for virtually every fish species, which is why they’re a staple in the aquarium trade.

Fishermen also prize bloodworms as premium bait. Roughly 121,000 tons of these marine worms are harvested each year, generating an estimated $7.5 billion in global revenue—more than triple what the U.S. sushi industry pulls in annually.

From a price‑point perspective, bloodworms are among the most expensive seafood items. A half‑kilogram (one pound) of live bloodworms can cost upwards of $80 in the United States, roughly four times the price of a lobster dinner.

8 Flukeworms

Consuming raw or undercooked freshwater fish that harbor liver flukes can lead to a chronic condition known as liver fluke disease. Approximately 35 million people worldwide are infected, suffering inflammation of the bile ducts and gallbladder that can linger for two to three decades.

The parasites are most prevalent across Southeast Asia—including Taiwan, Laos, Vietnam, South Korea, Thailand, eastern Russia and China—where an estimated 15 million Chinese are affected. While many carriers remain asymptomatic, severe cases feature fatigue, abdominal pain and a heightened risk of bile‑duct cancer.

Surprisingly, researchers have discovered a silver lining: flukeworms produce a specialized growth factor that encourages new blood‑vessel formation and tissue repair. The worms appear to secrete this factor to accelerate healing in their host, even as they feed on blood cells.

Scientists are now attempting to isolate this growth factor from the worm’s harmful components. The goal is to develop a wound‑healing vaccine that could treat chronic ulcers—especially those linked to diabetes—while also neutralizing the parasite’s carcinogenic properties.

7 Butterworms

Butterworms are the larval stage of a Chilean moth that is considered an agricultural pest outside its native range. Strict import rules keep them from establishing populations abroad, and low‑level radiation is applied to shipped larvae to prevent them from pupating and reproducing.

What sets butterworms apart is their strong, fruity aroma, which makes them irresistible to many fish species. Anglers often use them as bait for bass and panfish, where the scent and vivid coloration draw in even the most finicky feeders.

Beyond fishing, the same aromatic appeal makes butterworms a popular food source for reptile enthusiasts. Geckos, iguanas and other lizards readily accept these worm‑like treats, appreciating both the taste and the visual stimulus.

6 Mealworms

Mealworms have taken the concept of “homegrown food” to a whole new level. These beetle larvae are being farmed in kitchens worldwide as a sustainable protein source that rivals beef in nutritional value without the environmental toll of livestock farming.

Critics may balk at the idea of eating worms, but Livin Farms’ founder Katharina Unger likens them to “land shrimp.” She even notes that people allergic to shellfish should approach mealworms with caution, as the insects share some of the same allergenic proteins.

Livin Farms markets compact desktop hives that let users raise mealworms on kitchen scraps. The hives maintain a controlled microclimate, and LED indicators flash when the larvae have reached harvest size.

When prepared, mealworms offer a nutty flavor and a crunchy texture, making them a versatile ingredient for everything from protein bars to snack mixes. Their low carbon footprint and high feed‑conversion efficiency position them as a promising solution for future food security.

5 Red Worms

Vermicomposting (composting with worms) is a convenient way to dispose of organic waste. Homegrown compost is great for feeding and nurturing plants. This organic garbage disposal recycles food waste into garden soil conditioner by letting worms simply live as they normally would.

While many earthworm species can help break down waste, red wigglers excel at the task. Unlike night crawlers, which need supplemental food, red worms thrive on kitchen scraps alone, and under optimal conditions their population can double every ninety days.

All organic material naturally goes through the process of decomposition over time. But the process is significantly hastened by the nutrient‑rich vermicompost. Farmers can also predetermine the manure content. Feeding the worms with eggshells results in a calcium‑rich end product. Meanwhile, feeding them with coffee pulp leads to fertilizer rich in phosphorus and potassium.

Other red worm foods include tea bags, bread, all fruits apart from citrus, vegetables, grains, and cereals. It is also advisable to avoid feeding meats, dairy products, fats, and oils to the worms. Moisture plays an important role in the well‑being of worms, and 240 milliliters (1 cup) of water per day is recommended.

4 Fly Larvae

Italy may be famous for pizza and pasta, but Sardinia has a culinary curiosity that will make most tourists squirm: casu marzu, a cheese teeming with live maggots. The cheese’s fermentation is driven by fly larvae, which break down the fats and proteins, turning the curd into a soft, almost liquid substance.

Some diners choose to remove the maggots before eating, while others eat the maggots while they’re still moving. The cheese is considered unsafe once the maggots die, so it remains a controversial, illegal food within the European Union.

Beyond the cheese, maggots have a medical claim to fame. Maggot therapy involves cultivating sterile fly larvae and applying them to chronic wounds. The larvae secrete enzymes that liquefy dead tissue, then ingest the debris, effectively cleaning the wound from the inside out.

These secretions also produce antibacterial compounds that kill a range of harmful bacteria, making maggot therapy a powerful alternative to conventional antibiotics for stubborn infections.

3 Hookworms

Hookworms are tiny parasites that pierce human skin with tiny barbs, then journey via the bloodstream to the lungs. From there, they travel up the trachea, are swallowed, and finally settle in the small intestine where they latch onto the wall and sip a few drops of blood each day.

While residing in the gut, hookworms cleverly modulate the host’s immune response. They dampen overactive immune activity without shutting it down completely, which can inadvertently protect against autoimmune disorders.

In 2011, a pharmaceutical company launched a trial to see if controlled hookworm infection could reverse autoimmune conditions. The study showed no statistical difference between the worm‑treated group and a placebo group.

Nevertheless, anecdotal reports exist of individuals experiencing relief from allergies, hay fever, and Crohn’s disease after hookworm exposure. The downside includes occasional diarrhea and abdominal cramps, which may outweigh any potential benefits.

2 Silkworms

Silkworms entered human history roughly 8,500 years ago in ancient China, where people first learned to unwind the cocoons into a lustrous fiber. This precious silk was initially reserved for royalty, and its production secrets were fiercely guarded for millennia.

The craft spread to Korea by AD 300, later reaching Japan, and eventually Europe after monks smuggled silkworm eggs under the orders of Emperor Justinian. Over centuries, sericulture blossomed across the continent.

Modern science has taken silkworms a step further, genetically engineering them to spin spider‑silk proteins—something spiders can’t do in large farms because they’re cannibalistic. The resulting silk is stronger than steel and can absorb over 100,000 joules of kinetic energy.

One breakthrough product, dubbed “Dragon Silk,” has been used to fabricate lightweight armor for U.S. soldiers. The military funded the research with a $1.02 million contract, and the company continues to develop even tougher fiber variants.

1 Tapeworms

Tapeworms are flat, ribbon‑like parasites that live inside the digestive tracts of humans, dogs, livestock and fish. Infection typically occurs after eating raw or undercooked meat from an infected animal, but it can also spread through contaminated water or from person to person.

Once inside the host, the tapeworm latches onto the intestinal wall, absorbing nutrients directly from the host’s digested food. Some species can grow to astonishing lengths of 4.6–9.1 meters (15–30 feet) and live for up to twenty years.

While most people strive to eradicate tapeworms, a small subculture deliberately ingests them for rapid weight loss. The parasite steals nutrients, causing the host to lose 0.5–0.9 kg (1–2 lb) per week while still consuming calories.

After reaching a desired weight, patients pay roughly $1,500 in Mexico for a deworming drug to kill the tapeworm. However, the weight loss is often temporary; the parasite’s removal is typically followed by rapid weight gain, and the host may suffer vitamin deficiencies, a swollen abdomen, and in severe cases, death.

Bizarre and sometimes dangerous marine worms represent genuine monstrosities in animal form. These creatures can display the worst possible combination of being slimy and “toothy”. Prepare for a science‑fiction‑turned‑reality journey into the weird and wild world of water worms that slither and chomp their way through ocean life. 10 wicked worrisome creatures await your curiosity.

10 Wicked Worrisome Highlights

10 The Bootlace Worm

Too long to believe

Just how long can a worm get? Maybe try asking a Bootlace Worm next time you tie your laces at the beach. Reaching a crazy length of up to 180 feet, the Bootlace worm Lineus longissimus is not merely the longest worm on the planet. It is the world’s longest animal, period. Being the longest is not enough horror for this record‑breaker. The worm outdoes itself by being superbly poisonous to boot. The worm creates a potent toxin that is contained within the slimy mucous secreted by the worm. This hazardous chemical soup was found to be a peptide‑based compound in the course of investigation by Professor Ulf Göransson and colleagues at Uppsala University in Sweden. The primary toxin in the mucus could immobilize invertebrates such as crustaceans and insects. Interestingly, deadly peptides are found in cone shells from the tropics, but the discovery of bootlace worm toxicity represents a cold‑water example. The bootlace worm thrives in chilly waters off European coasts. As a poisonous rather than venomous animal, the bootlace worm is an interesting case given the worm’s use of poisonous mucus to hunt. Typically, a poisonous animal uses a toxin as a defense against being eaten, whereas a hunter would inject venom.

9 Osedax Worms

Oceanic Undertakers

Ocean‑going killers of cetaceans such as large sharks and Orcas might have some little accomplices in the form of worms that take care of the evidence. What happens to whale bones when they sink to the bottom of the sea? Why might it be hard to find many whale skeletons? They get eaten. Little marine worms called Osedax crave bone minerals and actually feed on the bones of whales. Nature lets nearly nothing go to waste and bone‑eating seems to be working well for these creatures.

The so‑called “Zombie worms” are a fairly new discovery, first observed in 2002 in the wild thanks to advances in deep‑sea exploration before being scientifically described in the lab in 2004. The worms were discovered at a depth of 10,000 feet feeding in a grey whale skeleton. Crazier yet, these creatures lack a stomach or a mouth. Osadex worms just secrete acid that melts bone, releasing meat‑like nutrients for the worms to take up through the work of symbiotic bacteria that proceed to break down the actual nutrients. Only females do the acid drilling, while males live inside the females as microscopic organisms. Would the worms eat a dead human? Pretty likely, since they have fed on cow bones at sea…

8 Piling Worm

Mating En Masse

When the lunar signals are right, huge marine worms common in the Pacific Northwest called Giant piling worms, grow up to a foot‑long swarm to the surface and mate. The majority of the time, the creatures stay hidden in the sand, collecting food with their pincer‑like jaws. Imagine swimming at night and being surrounded by foot‑long marine worms. No thanks.

The marine pile worm species was identified as Nereis brandti, a type of polychaete worm, according to Louise Page, a biologist from the University of Victoria in BC, Canada. Page listed sand‑dwelling habits as the typical behavior of the worms outside of mating season. The enormous size of the worms is off‑putting to would‑be adventurers, and reinforced by the presence of jaws which could deliver a painful bite thanks to the sharp appendages around the mouth. The swarming behavior gives rise to the fertilization of eggs and the appearance of tiny larval worms. Upon maturation, the worms may seem scary, but are actually most focused on eating algae. Their jaws are usually used to defend territory but offer only limited protection when the worms swim through the water, vulnerable to countless larger hunters.

7 Antarctic Scale Worm

Horror at the South Pole

Covered in bristles with dentacle jaws that look like something from the movie “Tremors”, the stubby, horrific‑looking Antarctic scale worm Eulagisca gigantea could certainly deliver a nasty bite. Growing nearly eight inches long, the marine worm’s scaly body acts as camouflage against the sea bed. But then it can rise up and attack prey with its proboscis which looks like a head with massive teeth. The hunter’s jaws efficiently rip into prey, serving as a powerful hunting tool that is a true concealed weapon. uses its jaws to rip into a variety of prey items, but if that is not enough, they are a true concealed weapon.

The worm can simply invert the appendage and pull it back into the body. Anytime there is an opportunity, outshoot the jaws. While the dentitions are not true teeth, being in an invertebrate, they are a pretty high‑quality likeness of a wolf’s fangs, albeit attached to a marine worm’s body. The creature is then partially beautiful in addition to being partially horrible‑looking. It is covered in bristly hairs that have a shiny golden appearance, offering an incongruous contrast to the worm’s monstrous capabilities. Prey items are simply ripped up by the sci‑fi‑worthy creature that has no problem remaining active in icy waters. With its fitting Latin binomial gigantea, the hefty creature can descend to depths of over 1,600 feet.

6 Fat Innkeeper Worm

The Ugly Guest Host

Known in common language as the Fat Innkeeper Worm, Urechis unicinctus is an awful‑looking creature, often compared to a penis in appearance. Yet its activities provide valuable habitat for a wide range of marine life that take refuge in the burrows they create. The bizarre worm is huge, bulbous, and beige and is named due to both its looks and the habit of creating horseshoe‑shaped burrows that serve as invaluable “inns” for a vast range of intertidal creatures. Gobies, other worm varieties, and even small crabs use the burrows, without harming or helping the fat innkeeper worm itself. The creature is a denizen of estuarine, brackish waters, and mudflats, hanging out around coastal wetlands that are unfortunately extremely vulnerable to climate change and development‑based disruptions.

The fat innkeeper worm feeds on plankton and is well known from the coast of California. Belonging to the phylum Echiura, the creatures may reach seven inches in length, large enough to startle beachgoers should be encounter one for the first time. In addition to maintaining “inns” for small creatures, the worms themselves are a veritable buffet course for larger visitors to wetlands, including bat rays, which suck up the worms, and opportunistic otters.

5 Multi‑Butt Worm

Ifs, Butts & Maybes

No ifs or maybes, but plenty of but(t)s? Yes indeed. There is a marine worm with one head and well over 100 derrieres, according to recent findings. The annelid worm species Ramisyllis multicaudata is distantly related to the familiar earthworm but inhabits oceans instead of gardens and lives in sea sponges that serve as hosts. Research published in the Journal of Morphology describes how the worms use the hollowed‑out interiors of marine sponges, an even simpler life form as a place of residence. How the worms feed is a matter of further research interest, given the lack of digested food found in the digestive tracts of the marine worms upon examination.

What is well documented is the importance of the many butts of the worms in reproduction, but not in the way you might expect. Each worm butt actually breaks away eventually and develops eyes and a brain before developing into a brand new worm that starts the life cycle over again. In extreme cases, the number of rears on a Ramisyllis multicaudata worm could be far more than reasonable imaginable. Up to 1,000 rear ends may be part of one worm.

4 The Burning Worm

Fire Under the Sea

Danger often comes in small bundles and that is the case with certain marine worms. While they only grow up to be about three to four inches in length, the worm community’s answer to the lionfish, scorpion, and stinging nettle is nothing to mess with. Found in warm tropical waters, Bearded fireworms Hermodice carunculata are covered in horrifying bristles that unload venom onto anyone or anything unlucky enough to touch them. Ouch! These toxic sea creatures are associated with Western and limited central Atlantic habitats that include coral reefs, under rocks, and even nestled in flotsam and jetsam drifting along the waves at sea.

The awful bristles are shiny and beautiful, having a resplendent appearance similar to a lionfish or sea anemone.  The worm’s hollowed‑out bristles effortlessly slide into the flesh of any creature that comes into contact with them and snap away, leaving bristles embedded. This causes mechanical and chemical irritation akin to being stung by a bee. To be fair, the worms do give out a warning first if bothered by first flaring out their bristles. Clearly, one of the laws of the sea to remember at all times is when in doubt, do not touch!

3 Parchment Worm

The Animal, The Machine

Looking like a literal paper dragon, the parchment worm Chaetopterus variopedatus constructs its burrow out of an extension of its body. While fragile, it is a strange mix of graceful and absolutely grotesque. The creature is gentle and feeds on plankton that it traps, and is not an aggressive hunter like many of the tougher worms in this account. Growing to about 10 inches in length, the worm is a bizarre but successful animal as a globally distributed generalist found in both tropical and cooler waters.

The feeding strategy of the parchment worm is decidedly odd. The worm’s body is formed by three sections, which include mouth and bristly body segments. Next, there is a structure that forms mucous and secreted mud‑based bags in the center, with segments that pump water into the body tube. Finally, a third section made up of many segments in a row concludes the body plan. The remarkably mechanical animals simply bag up food filtered from the water in mucous and mud “capsules” and swallow them like pellets for digestion.

2 Spaghetti Worm

A Rebel Among Worms

If you dumped a bowl of noodles on the seafloor, you would have a crazy‑looking creature that looks exactly like either spaghetti come to life, or even a crawling mop head. All you see are the tentacle‑like extensions as the worm winds along the seabed in search of meals. Unlike many marine worms, the spaghetti worm spends its life in the open, not needing the protection of a burrow. The creature is still in the process of being given a species name.

The discovery of the creature is fairly new, with the first sighting and description taking place during a research trip in the Gulf of California by the Monterey Bay Aquarium Research Institute (MBARI). This “dancing mop” may look vulnerable but apparently, the array of appendages allows the worm to collect small food items, all without having any eyes! The worm is a type of polychaete marine worm and belongs to the genus Biremis. Given the importance of polychaete worms in the marine environment, there is a World Polychaete Day which is July 1st to celebrate their existence. Footage of the mysterious Biremis species was first released on July 1st, 2012, nine years after MBARI researchers discovered it, marking the special day.

1 The Bobbit Worm

Worse Than Science Fiction

What creature bursts from the sea floor and grabs or even saws or scissors its prey right in half? The horrific Bobbit Worm Eunice aphroditois, armed with massive fangs that have a convergent resemblance to teeth can slice fish in half, right through the spine, and deliver a nasty bite if provoked. Stinging bristles just add to the nightmare. The worm is also dangerous to humans and should be viewed with great respect, not just curiosity. Drably colored segments of the worm are accented with iridescent highlights that add a dash of beauty to unimaginable ugliness.

The worm is akin to a viper, equipped with massive fang‑like pincers that are attached to the head. The force generated by the bite combines with the shocking striking speed to make encountering this animal a little bit like brushing into an underwater mine. In addition to the risks posed by a bite, the toxic bristles are capable of causing long‑term nerve damage if the animal is handled unwittingly. Disturbingly, this animal can on occasion reach 10 feet in length and weigh around one pound in the most extreme cases. That said, it is certainly possible larger and more vicious specimens are waiting to be discovered.