Earth’s magical ecosystems might be on their way out, but they’re still full of awesome surprises — like these ten animal behaviors, each of which is so totally opposite to what you’d expect that they’re practically oxymoronic.
10 Flying Squid
Often mistaken for flying fish, there are at least six known species of flying squid and possibly dozens more. But because catching a glimpse of them in the wild is a blink‑and‑you’ll‑miss‑it affair, scientists rely heavily on sailor anecdotes that report squid landing on decks at dawn.
Marine biologist Silvia Maciá got lucky on a 2001 holiday when a Caribbean reef squid, startled by her boat’s noise, shot out of the water and arced through the air. She gauged the creature’s ascent at two meters high and a ten‑meter glide— roughly fifty times its own length. Yet this wasn’t a mere hop; the squid “extended its fins and flared its tentacles in a radial pattern while airborne,” steering its flight like an inside‑out bird. In their joint paper, Maciá and co‑authors argued that “gliding” underplays the act, insisting that ‘flight’ is a better descriptor because it implies active propulsion.
Co‑author reports even claim to have seen squid flapping fins as if they were wings, and using powerful water jets for extra thrust— sometimes enough to keep pace with boats. Flocks of flying squid have also been observed. While the exact reason remains uncertain, the prevailing hypothesis is that aerial movement conserves energy while evading predators.
9 Walking Bats
Although mammals, bats have adapted so thoroughly to flight that their “legs” are essentially attachment points for wing membranes, making terrestrial locomotion a challenge. In most bat species, crawling is a laborious effort.
Out of the 1,110 bat species, only two possess a true walking gait: the vampire bat and the lesser short‑tailed burrowing bat. For vampire bats, walking is vital; after alighting near a sleeping host, they must stealthily creep to feed on blood, and some can even run, using their wings for added thrust.
The lesser short‑tailed burrowing bat of New Zealand showcases remarkable adaptations for walking, including grooved soles, clawed toes, and wing‑holding pockets. This species spends roughly 40 percent of its foraging time on the ground, yet it can still fly as adeptly as any other bat— a contrast to birds, which sacrifice flight efficiency for terrestrial specialization.
8 Bat‑Catching Snakes
Since most bats cannot walk and snakes cannot fly, one might assume their paths never cross. Yet a population of yellow‑red rat snakes in a Yucatán cave has taken to hanging from ceiling cracks, dangling to snatch passing bats.
The dense nightly bat swarms exiting the “Bat Cave” make this aerial hunting strategy viable. Similar behavior occurs 1,000 km away, where Caribbean boas seize fruit bats from cave ceilings, often coordinating in packs to maximize capture success.
7 Fish‑Eating Spiders
Although some spiders are known to eat frogs, rodents, and birds, the notion of a spider preying on fish may sound far‑fetched. A comprehensive review, however, lists five genera spanning every continent except Antarctica that specialize in fish capture.
In North America, semi‑aquatic spiders anchor their hind legs to stones or plants and “fish” with front legs on the water surface, snaring tiny freshwater mosquito fish. After hauling the catch ashore, they often spend several hours feeding because the fish are typically at least twice the spider’s length.
6 Hornet‑Cooking Bees
Stinging isn’t the only extreme defense employed by bees. When a hornet invades a nest, hundreds of worker bees swarm the intruder, forming a tight ball that generates intense heat to roast the predator alive. This phenomenon, called “hot defensive bee balls,” was first documented in detail in Japan in 1995.
By rapidly vibrating their wing muscles for up to half an hour, bees raise the temperature inside the ball to about 46 °C— just enough to kill the hornet. While this heat is just below the lethal point for the bees themselves, it shortens their lifespan and appears to lower neurological inhibition, making them more prone to join future defensive balls.
Some bee species also use non‑heated balls to suffocate attackers or create shimmering wave dances that signal danger to conspecifics. However, hornets can release pheromones to summon reinforcements, so speed is essential for the bees.
5 Sea‑Faring Spiders
One would assume spiders avoid water, yet many thrive near or even within it. The diving bell spider constructs an underwater silk dome that traps air bubbles from the surface, maintaining a stable oxygen supply through diffusion from nearby aquatic plants.
Even more astonishing, coastal spiders of the genus Amaurobioides travel across oceans. Using their legs as sails and silk as anchors, they can drift thousands of kilometers, explaining their presence from South America to South Africa during the Miocene, and later to Australia and New Zealand. This behavior also sheds light on Darwin’s observation of spiders appearing on ships far from shore.
4 Immaculately‑Conceiving Komodo’s
In 2006, a startling report in Nature described two captive female Komodo dragons in English zoos reproducing without male contact. One laid eleven eggs, eight of which developed normally; the other produced twenty‑two eggs, four of which hatched. Though the second dragon had mated two and a half years earlier, genetic analysis revealed the offspring were clones of the mother— all male— confirming parthenogenesis.
Parthenogenesis, a form of asexual reproduction, is exceedingly rare, occurring in only about 0.1 percent of vertebrates. For Komodo dragons, isolated island habitats likely favor this ability, allowing a single female strand‑washed onto a new island to establish a population.
Unfortunately, parthenogenetic offspring suffer from reduced genetic diversity, making them more vulnerable to disease. Moreover, the sex determination system in Komodos (ZZ = male) means all parthenogenetic hatchlings are male, offering little advantage for the endangered species.
3 Bird‑Catching Fish
Sharks aside, fish are usually the prey, not the predator, of birds. However, in 2014 South African researchers filmed a tigerfish leaping from a lake to snatch a swallow mid‑air—the first confirmed instance of a freshwater fish capturing a bird in flight. The team observed up to twenty such strikes per day, indicating that avian predation by fish is more common than previously thought.
Another avian‑predating fish, the silver arowana, also targets birds, as well as bats and even mice, exploiting its powerful leap and sharp teeth within the dwindling Amazon rainforest.
2 Land‑Stalking Fish
Birds aren’t safe from fish on dry land either. On a small island in France’s River Tarn, European catfish ambush pigeons that come to preen. These catfish, typically 1–1.5 m long with some specimens reaching three meters, are Europe’s largest freshwater fish and display remarkable adaptability.
Using their barbels— sensory “whiskers”— to detect vibrations, catfish swim near the island, then launch themselves onto land, seizing any pigeon that moves. The entire ambush, from splash to capture, takes under four seconds before the catfish retreats back into the water.
1 Tree‑Climbing Fish
Defying the age‑old adage “a fish out of water,” Asian mudskippers can survive on land for up to two days by retaining water bubbles in their gill chambers and breathing through both gills and moist skin. Their specially adapted fins enable them to walk or hop on solid ground, and their vision actually improves out of water.
Recent studies have revealed that certain mudskipper species, such as the dusky‑gilled and slender varieties, can also climb trees. They achieve this feat through a combination of suction, friction, slime‑like secretions, and fin movements, allowing them to ascend vertical trunks.
Even more astonishing is their ability to traverse water surfaces. Observations of the dusky‑gilled mudskipper in Java show it leaping from mangrove roots onto water, then propelling itself to another vertical incline, reaching speeds of 1.7 m s⁻¹.