Insects have several defensive manoeuvres and unusual strategies for avoiding and fooling their prey so that they can survive another day. Some, like caterpillars, can even appear to be dead. So, in this case, do caterpillars play dead as a strategy to avoid predators or are they really just dead?
Yes, caterpillars do play dead. Almost all caterpillars play dead as a defensive manoeuvre to avoid predators as predators don’t like to feed on dead prey.
When a caterpillar feels threatened by another creature such as a bird, fox, raccoon, or any rodent, then it can perform several defensive strategies to scare off the predator, or the caterpillar naturally could have something that helps it avoid predators.
Some caterpillars have bright colours that warn other creatures that they might be poisonous, so no animal eats them. The caterpillar could have small thorns or fake eyes that scare the predators away.
Similarly, thanatosis is a strategy used by caterpillars and many other insects to act as if they’re dead. When a predator sees a dead caterpillar, it leaves it alone.
What is Thanatosis?
Besides scavengers, predators don’t like to eat something that is dead already. They’re interested in alive prey. Hence, to avoid predators, insects have a strategy of playing dead. This strategy is performed by almost all kinds of caterpillars. This strategy is called thanatosis.
Caterpillars perform thanatosis when they feel threatened by another animal. They’ll stop whatever they’re eating and let go of the leave, twig, or anything they’re holding on to.
After reaching the ground, the caterpillar will curl up and stop moving, pretending to be dead.
They do this until the predator gives up, believes that the caterpillar is dead, and leaves. This strategy works most of the time.
If you found a caterpillar in your yard and it was perfectly fine at first, but then suddenly, it acted as if it died, then don’t worry because you didn’t kill it. The caterpillar just got scared and acted on its natural instincts near a predator.
What Other Defences Do Caterpillars Have?
Playing dead in front of predators, so they lose interest and go away, isn’t the only defensive strategy that caterpillars have. Different species of caterpillars have different varieties of defensive strategies to scare off or avoid predators.
Stinging
Most people assume bees and wasps are the only stinging insects out there, but in reality, several species of caterpillars are equipped with tiny poisonous stingers on their bodies.
Caterpillars often have spines and barbed hooks. In some species, they’re mostly for having an intimidating appearance, so predators such as birds stay away.
Some caterpillars, however, have much more dangerous quills. They’re hollow pointy hairs that are connected to poison sacs. These quills are a useful defensive weapon for a caterpillar at times like if a predator is brave enough to pick up the caterpillar even though it has stings, the quills will pierce the skin, releasing the poison when touched.
Reactions can vary as sometimes the sting victim only has a mild itching, but sometimes the pain is much more severe. You can suffer from blistering, swelling, dermatitis, and even disturbance in the intestines.
An example of a poisonous caterpillar with stings is a Puss Caterpillar. This caterpillar looks very cute but no matter how much you want to hold it, avoid touching it as it’s poisonous. These caterpillars have a dense fur coat of bushy hair, but there are several short poisonous spines beneath this dense hair.
These spines can cause severe irritation and itching. They are sometimes seen on shrubs and trees, and young ones often feed in groups, so you might spot a bunch of them.
The severity of the poisonous sting increases with the size of the caterpillar. If you spot a pretty big puss caterpillar, then it’s best to have a safe distance from it as the bigger its size, the more dangerous it can be. These caterpillars have much more severe stings than many other stinging caterpillars.
Poison
Some caterpillars get poisonous after eating poisonous plants such as milkweed. They store the poison inside their bodies and become poisonous themselves. Predators often ignore these caterpillars due to their poison, and in this way, the caterpillar survives.
Bright Colours
In the animal kingdom, the insects that have very bright colors most often are poisonous, and all other animals know about it. Predators stay away from brightly coloured insects for fear of their poison.
Many species of caterpillars have brightly colored patterns and are poisonous, and if they’re touched, the symptoms can be severe.
An example of such a caterpillar is a saddleback caterpillar. It has a small body, and sort of resembles a slug. The caterpillar is brown, but there is a very noticeable bright green patch on the middle of its back. There’s an oval red-shaped mark on the middle of the green patch.
The many horns filled with several spines are very noticeable on the head and tail of the caterpillar as well. These spines and horns are very poisonous, and the poison can damage blood cells. Even a little touch can cause severe asthma, stomachache, and even bleeding.
Fake Eyes
Some caterpillars have a large pattern on their thorax in the form of eyes. If you look at one of these caterpillars from a distance, they look like intimidating eyes. These caterpillars use these eyes to their advantage and scare off predators.
Summary
Like most insects, caterpillars have several strategies to avoid predators or scare off predators so they can stay alive long enough to turn into a butterfly.
Caterpillars have a defensive strategy called thanatosis, where they pretend to be dead, so the predator loses interest and leaves them. Some species of caterpillars have poisonous bodies, thorns, and quills to defend themselves against predators, and some even have fake body parts like fake eyes to look intimidating.
