• Science

10 Amazing Insect Defensive Tactics

It's not easy being at the bottom of the food chain. Insects have predators coming at them from all sides, so they've cooked up a whole bunch of ways to defend themselves. When you're tiny, you need to be tough. That's why insect defense mechanisms are so strange, effective, and often downright amazing.

How do insects protect themselves? Some of these techniques are pure offense, but most of them have evolved into remarkable defenses. Hiding, fighting, playing dead... nothing is off the table when it comes to survival. These are 10 ways insects protect themselves.
  • Acting

    No, really, I'm dead. Just lying here, deceased and unmoving. Move along, nothing to see here but us dead bugs.

    Things that eat other things tend to quickly lose interest in dead prey, so some insects that employ the strategy of playing dead (thanatosis) can often escape unharmed. Threatened insects simply let go of whatever they happen to be hanging on to and drop, motionless, to the ground where they put on the performance of a lifetime. Certain caterpillars, ladybugs, many beetles, weevils, robber flies, and giant water bugs all employ this technique. Guess what Death-feigning beetles do to protect themselves?
  • Photo: Michael Holroyd / Wikimedia Commons / Public Domain

    Acid & Burning Agents

    Some bugs release irritants so awful that it automatically makes "get it off! get it off!" the only thing a predator thinks. It's not the most romantic defense mechanism, but it gives the insect time to escape. Some blister beetles produce a blistering (hmm, I think I know how they got their name) agent. Droplets of this will ooze from the beetle's leg joints when it is disturbed or threatened -- an adaptation known as reflex bleeding. Some termites, cockroaches, earwigs, stick insects, and beetles will literally spray acid at attackers. The (fantastic) bombardier beetle stores chemicals in specialized glands, and when threatened, mixes them together to produce a forceful discharge of boiling hot quinone and water vapor (steam). Seriously. That is @$#% awesome.

    Some caterpillars have hollow body hairs that contain a painful irritant. Simply brushing against the pretty, soft-looking fluff will cause them to break and get all over your skin, resulting in an intense burning that may last for several hours. Many ants, bees, and wasps deliver venom to their enemies by means of a formidable stinger (modified ovipositor). The venom is a complex mixture of proteins and amino acids that not only induces intense pain but may also trigger an allergic reaction in the victim.
  • Photo: Deepugn / Wikimedia Commons / CC BY-SA 4.0

    Speed & Movement

    Some insects don't have fancy weaponry or acting chops and have to rely on speed to get away. For many insects, a quick escape by running or flying is the primary mode of defense.

    Sure, Mr. Miyagi can catch flies with chopsticks, but can you? House flies have an insanely fast reaction time when you try to swat them. They can fly away 30-50 milliseconds after sensing a threat! And a cockroach? Those nasty things have tiny, super-sensitive hairs that are acute enough to detect the change in air pressure that might occur right before you try to step on them. It can react in less than 50 milliseconds. Just try and hit them with a newspaper. You can't do it.
  • Armor & Spines

    Plenty of insects simply rely on their exoskeleton to avoid being eaten.

    Large weevils have ridiculously strong armor and can actually bend insect pins when bug collectors try to add them to their boards. The Ironclad Beetle can literally be stomped on, and take zero damage. These guys don't just bend those insect pins, you need a drill to get through their shell. Then there are spines, bristles, and hairs that work pretty damn good in discouraging things that might be hungry. Nobody wants a mouthful of needles, and the hairier insects make for an unpleasant dining experience as well. Plus, insects like super-hairy caterpillars make it super difficult for parasitic flies or wasps to even get close enough to the insect's body to lay their eggs.