12 Bizarre Defense Mechanisms Found in Nature

The Texas horned lizard has more than just a thorny exterior to defend itself. It also has a surprising (and bloody) trick for predators. . reptiles4all/Shutterstock

Opossums will play dead by going into a coma. Some lizards will let part of their tail drop off to escape a predator. Quite a few bird species will throw up stinky liquids to deter their enemies. Sure, these are smart strategies, but they're practically cute compared to some of the things other species are willing to do to stay alive.

Texas Horned Lizards Shoot Blood From Their Eyes

You may have heard of this behavior and thought it was just a myth, but it's true. The Texas horned lizard, also known as a horny toad, is able to squirt a well-aimed stream of blood from the corner of its eye to deter a predator. Ask Nature explains how it works:

"The horned lizard has two constricting muscles that line the major veins around its eye. When these muscles contract, they cut off blood flow back to the heart, while it continues to flow into the head. This floods the ocular sinuses with blood, building pressure, and causing them to bulge. By further contracting these muscles in a rapid manner, the pressure increases even more, eventually rupturing the thin sinus membranes. The result is a jet stream of blood that can shoot up to four feet from the eye socket, a process known as auto-hemorrhaging. Amazingly, this process can be repeated several times within a short period if necessary, though the mechanism for this rapid recovery is not completely understood."

You might be wondering if there's a video of such weird behavior. Why, yes; yes there is.

The defense mechanism hasn't been enough to protect the species against humans, however. The horned lizard has experienced an alarming decline due primarily to habitat loss but also due to collection for the pet trade. The Texas horned lizard is now a protected species in Texas.

Iberian Ribbed Newts Push Ribs Through Their Skin

This unusual species of newt uses its own ribs as a weapon.
This unusual species of newt uses its own ribs as a tool to ward off predators. Peter Halasz/Wikimedia Commons

While some species squirt blood at predators, others use their own bones as weapons. The Iberian ribbed newt has an amazing, if disturbing, way of dealing with predators. When threatened, the newt can push its ribs forward and through its stretched skin to create defensive spikes. But not just any spikes — these are poisonous. "When teased or attacked by a predator, [the newt] secretes a poisonous milky substance on to the body surface. The combination of the poisonous secretion and the ribs as 'stinging' tools is highly effective," Egon Heiss, zoologist at University of Vienna in Austria, told BBC News.

While the attacker gets a mouth full of poisonous spines that cause severe pain or possibly even death, the newt itself experiences no significant negative affects from the gruesome strategy. It can perform this skin-piercing maneuver over and over again during its life and heal itself each time without problem.

Hairy Frogs Break Their Own Finger Bones for Claws

This frog species will break its own bones to create claws for self-defense.
This frog species will break its own bones to create claws for self-defense. Gustavocarra/Wikimedia Commons

There's a good reason why this frog is often called the "horror frog" and the "wolverine frog." When threatened, the hairy frog's main defense is to crack its own finger bones, pierce them through the skin of their toe pads, and use them as claws — not unlike Wolverine of "X-Men" fame, and definitely falling into the horrific category.

David Blackburn at Harvard University’s Museum of Comparative Zoology explained it to New Scientist:

"At rest, the claws of T. robustus, found on the hind feet only, are nestled inside a mass of connective tissue. A chunk of collagen forms a bond between the claw’s sharp point and a small piece of bone at the tip of the frog’s toe. The other end of the claw is connected to a muscle. Blackburn and his colleagues believe that when the animal is attacked, it contracts this muscle, which pulls the claw downwards. The sharp point then breaks away from the bony tip and cuts through the toe pad, emerging on the underside."

This behavior is unique among vertebrates, and would certainly come as a surprise to an attacker.

Exploding Ants ... Well, Explode

The Malaysian exploding ant does exactly what its name implies.
An exploding ant's namesake behavior releases a toxin inside its abdomen. Noel Tawatao/Wikimedia Commons

Ant colonies have different types of ants filling different roles, including ants whose job is to defend the colony against attackers. But for about 15 species of ants in Southeast Asia known collectively as "exploding ants," defending the colony means more than just biting attackers with their mandibles.

Worker ants from these species have large, poison-filled glands that run down the length of their bodies. When under threat, a worker ant will violently contract its abdominal muscles to essentially blow itself up and spray the sticky poison on the attacker. It may not be a Hollywood-esque ball of flames, but the explosion itself isn't what's dangerous — its only purpose is to release the corrosive chemical irritant, which can immobilize or kill the attacker.

Although this also kills the ant, her action can help save the entire colony. Whether or not the exploded ants are honored with a hero's burial is unknown.

Bombardier Beetles Spray Boiling Hot, Toxic Liquid

This is another species that sprays a noxious substance, minus the drama of dying in the process. That's because in this case, it's an individual defense mechanism rather than one that benefits the colony, so dying in the process would defeat the purpose.

The bombardier beetle doesn't just spray something that smells bad, like a stink bug. It takes the substance to a whole other level. Bombardier beetles send a scalding hot chemical spray all over their attacker.

The National Wildlife Federation explains:

"An important feature of these beetles is the presence of two chambers within their abdomen that keep the critical reactants apart until they are ready to be discharged. When the beetle feels threatened, the contents of these two chambers are combined and fired through the abdominal tip. Without two separate chambers, the beetle wouldn’t be able to survive! The abdominal tip through which their defensive chemical is sprayed can be rotated 270 degrees so that they can more easily fire at predators."

The spray from the bombardier beetle is as hot as the boiling point of water. This video describes how the beetle accomplishes such an extraordinary feat:

Termites Grow Exploding Backpacks of Toxic Liquid

Okay, one more exploding insect before we move on to other defense mechanisms, and this one is quite spectacular. A type of termite found in French Guiana called Neocapritermes taracua spends its life readying for an attack. When it happens, the older termites head to the front lines because they are particularly prepared to fight back — not because they're more experienced at combat, but because they're packing heat.

The Week explains:

"The termites are equipped with what are essentially 'explosive backpacks.' Over their lifetime, the termites produce toxic blue crystals using a pair of glands in the abdomen, and then store them in an external pouch. When enemy termites, such as Labiotermes labralis, attack the nest, older worker bugs are sent to the front lines along with soldier bugs. The poisonous blue crystals they have amassed react with salivary gland secretions to create a type of 'toxic goo.' When an enemy takes a bite, the explosive backpack ruptures, covering nearby foes in a deadly, paralyzing venom that also kills the worker in the process."

The older termites are the first responders because they have the largest accumulation of the toxic crystals, which means they'll pack a bigger punch against enemies. Much like the Malaysian exploding ant, their sacrifice can help save the colony.

Is there a video of that, too? Of course there is.

Flying Fish Take to the Air at 37 Miles Per Hour

Flying fish leave the water entirely in order to escape trouble.
Flying fish leave the water entirely to escape trouble. feathercollector/Shutterstock

While there is the option of breaking one's own bones or blowing oneself up, there is also the concept of escaping entirely. For one species of fish, that means ditching the water and taking to the air.

The flying fish has an extraordinary method of evading predators. The small fish, the largest of which grow to only about 18 inches long, swim at speeds reaching 37 miles per hour to launch themselves from the water. "Angling upward, the four-winged flying fish breaks the surface and begins to taxi by rapidly beating its tail while it is still beneath the surface," reports National Geographic. "It then takes to the air, sometimes reaching heights over 4 feet (1.2 meters) and gliding long distances, up to 655 feet (200 meters). Once it nears the surface again, it can flap its tail and taxi without fully returning to the water."

Flying fish can keep up these consecutive glides and stretch a single flight out to distances reaching 1,312 feet! A fish that takes to the air for over a thousand feet is certainly an extraordinary adaptation.

Sea Cucumbers Push Organs Out of Their Anus

Instead of taking to the air, you could just gross out the predator. That's what sea cucumbers do. It takes guts to do this — literally. Sea cucumbers utilize a defense mechanism called self-evisceration in which they eject their intestines and other organs out of their anus. The long intestines distract, entangle, and can even harm the enemy since, in some sea cucumber species, the intestines are poisonous. Predators may think that the sea cucumber is dead, and the organs expelled keep the predator busy while the sea cucumber leaves the scene. Though it looks pretty terrible, the sea cucumber isn't harmed in the process. The organs can be regenerated within a matter of weeks.

These divers poked a sea cucumber and videoed the results (and we hope they also apologized to the sea cucumber and left it alone shortly after).

Hagfish Choke Predators With Slime

The hagfish has a sticky solution to getting out of trouble. When threatened, the hagfish expels a thick slime that mixes with the water. The predator then needs to focus on escaping the gill-clogging goo. While the predator gags, the hagfish slips away. You can see how incredibly viscous the slime is in this video, which clears up any uncertainty about its ability to suffocate attacking fish.

And here it is in action in the wild. Something amazing pointed out by the researchers behind this video is that of the 14 observed attempts for a predator to prey on a hagfish, not a single one was successful. The hagfish won every time. It's clearly a great solution since the hagfish has been around for some 300 million years.

Millipedes Glow in the Dark and Ooze Cyanide

This species of millipede glows in the dark as a way to warn away predators.
This millipede glows in the dark as a way to warn away predators. Eden, Janine and Jim/Wikimedia Commons

A defensive strategy for many animal species is to have vivid colors or patterns that warn off would-be predators. But what if you spend much of your life in the dark as a nocturnal creature? Colors won't do much good in that kind of environment, so you'll have to put on a light show. That's what this species of millipede of the genus Motyxia does. It has a bioluminescent glow to warn away predators. Predators would be smart to take heed. Why?

"When they are disturbed, they ooze toxic cyanide and other foul-tasting chemicals from small pores running along the sides of their bodies as a defense mechanism," Paul Marek, a research associate in the University of Arizona's department of entomology and Center for Insect Science, told UANews.

Glowing in the dark and oozing cyanide is certainly one of the more original defense mechanisms of the animal kingdom.

Boxer Crabs Use Sea Anemones Like Deadly Pom-Poms

The pom-poms on the end of this crab's claws are actually anemones.
The pom-poms on the end of this crab's claws are actually anemones. Hans Gert Broeder/Shutterstock

What if you want to use poison to defend against attackers but don't make any yourself? The boxer crab, also known as the pom-pom crab or cheerleader crab, came up with a clever solution. Boxer crabs pick up and carry around a tiny sea anemone in each claw. When disturbed, the crab will wave the anemones to warn off predators but if the predator attacks, the anemones pack a powerful sting. It's a great way to keep attackers at bay, and the anemones benefit by becoming mobile and thus potentially gaining access to more food. But it's not like the anemones have much of a say about it anyway.

Boxer crabs don't have to have anemones to survive, and sometimes they'll use coral or sponges instead. Here is a boxer crab waving its pom-poms (and a fish being wise by giving the crab its space):

Acacia Trees House Aggressive Ants in Hollow Thorns

The thorns of the acacia tree not only look unpleasant on the outside, but house unpleasant ants on the inside.
The thorns of the acacia tree not only look unpleasant on the outside; they house unpleasant ants on the inside. Angel DiBilio/Shutterstock

It's not just animals that use other animals to help defend against attack. Plants do it too. For acacia trees, their attackers are grazing animals, and their defenders are ants.

This symbiotic relationship exists among several species of acacia and ant One example is the bullhorn acacia and the ant species Pseudomyrmex ferruginea. The ants live in the large, hollow thorns of the tree. When a browsing animal starts nibbling, the ants come out and swarm it, driving the grazer away with bites and stings on the sensitive mouth area. In return for protection, the tree provides food in the form of nectar and protein-lipid nodules called Beltian bodies. Though the acacia trees are still grazed to some extent, the ants keep browsing animals from eating too much.

The ants seem to do more than just keep browsing animals away. They also seem to improve the health of the acacia tree overall. According to a recent study, "The presence of mutualistic ants greatly reduces bacterial abundance on surfaces of acacia leaves and has a visibly positive effect on plant health. Study results indicate that symbiotic bacteria colonizing the ants inhibit pathogen growth on the leaves."

The acacia trees may have something to worry about, however, as their little body guards are falling victim to another species of invasive ant called the bigheaded ant. After winning a violent war against the acacia tree ants, "The bigheaded ants, Pheidole megacephala, stay a while in the acacia trees before returning to their nests, preventing native species from recolonizing the trees," reports the New York Times. "The researchers report that as a result, the rates of elephant damage to trees in invaded areas is five times higher than in areas where native ants reign."

Without the ants, the acacia trees are over-browsed by hungry herbivores, and without acacia trees, the savannah won't be able to support large herbivores. So the real defensive strategy may need to be mounted by humans against the new ant invaders, so that the acacia ants can continue to do their symbiotic duty to protect the trees.

When disturbed, the ants appear on the acacia tree and deter grazers.
When disturbed, the ants appear on the acacia tree and deter grazers. Angel DiBilio/Shutterstock