20 Facts about Caterpillars

I wrote down 20 facts about Caterpillars to explain their physical characteristics, advantages, and disadvantages.


1. Caterpillars are not full-grown insects.

They are larvae of a butterfly or moth. That means, once they grow up, they become either a butterfly or moth.

2. Caterpillar body consists of three parts: head, thorax, and abdomen.

They have 6 legs and several prolegs which are considered fake legs. Their body structure is described in the image below:

Caterpillar facts
A – head, B – thorax, C – abdomen, 1 – prothoracic shield, 2 – spiracle, 3 – true legs, 4 – midabdominal prolegs, 5 – anal proleg, 6 – anal plate, 7 – tentacle, a – frontal triangle, b – stemmata (ocelli), c – antenna, d – mandible, e – labrum. (photo credit: Wikimedia)

3. Caterpillars have a large appetite.

They eat all the time in order to gain enough energy to prepare their body for the next development stage. Most of the caterpillars are herbivorous. Meaning, they only eat plants. However, a few kinds are considered insectivorous (animals that eat insects).

4. They eat leaves of fruit trees and vegetables.

That is how they cause a damage. They eat the plants and deprive them of growth. Detecting a caterpillar in your garden, especially if you see one veraciously eating the leaves out of your garden, is not a good sign.

5. Caterpillars do not have a bone in their body.

Despite the absence of bones, caterpillars can walk using their muscles and making the wavy motions with their body.

6. Caterpillars usually are mistaken to larvae of bees, wasps, and ants.

Although larvae of other insects may look similar, you may still differ caterpillars easily by inspecting their abdominal segments. If the insect you are looking at is truly a caterpillar, then it should have prolegs attached abdominal segment.

7. Caterpillars camouflage in order to protect themselves from predators.

No wonder why we see caterpillars with so many different colors and textures. Interestingly, caterpillars can get the color of the plants they eat. As result, they can blend with the color of plants making themselves almost unnoticeable.

Caterpillar insects
(Photo credit: Wikimedia)

8. Caterpillars release toxic smell to deter predators.

For instance, one kind of caterpillars, hornworms, eat the nicotine plants. As toxic as it is, how can a caterpillar survive after eating it? Scientists are also interested in finding an answer to that question. After the research, scientists found that the caterpillars turn the consumed nicotine leaf into the toxic smell that can serve them as a defense mechanism.

9. Caterpillars have setae (or hair) that makes them unpleasant for swallowing

Despite their slow movement, interestingly, they are not the easiest victims for birds. As I mentioned above, some of them release toxic smell to scare off the predators, while some camouflage themselves to become almost invisible inside the plants. Now, we know that even if the predators found them and not mind eating them with their toxic smell, they still have to worry about swallowing them.

10. Paper wasps, European pied flycatchers, and some spiders are the worst enemies of caterpillars.

Paper wasps catch them to feed their young ones and themselves. Flycatchers also hunt them among oak foliages.




11. Some of the caterpillars are poisonous enough to hurt people seriously or even kill them.

Some of the poisonous caterpillars are the Puss caterpillar, Buck moth, Gypsy moth, io moth, Saddleback, and Flannel Moth. These ones are more common in the US territory. However, they can also be found in many other places.

Giant silkworm moth, for example, is considered one the deadliest caterpillars in the world. Released toxic from their setae can cause internal bleeding and can lead to death. This kind of caterpillars, however, mostly found in South America.

12. Some caterpillars become buddies with ants for protection.

According to the research, caterpillars bribe the ants with their secretion in order to make them their bodyguards. The research was conducted to learn the relationship between these insects in depth. Scientists found that ants which ate the caterpillar secretion acted aggressively against the spiders that are trying to approach their buddy caterpillar.

13. Caterpillars grow very fast.

They take “eat big to get big” approach and eat like machines. Some caterpillars are capable of doubling their sizes in a few days.

14. Caterpillars change their skin several times.

Caterpillars don’t do that for fashion. They change their skin because they grow so fast that they do not fit to their own skin. So, they had to shed their old skin and get a new one with new texture and color. Caterpillars shed their skin 4 (four) times until they are finally ready to move on the next stage.

15. Caterpillars turn into a pupa.

Caterpillars turn into a pupa before they become full-grown butterflies or moths. In other word, caterpillars do not stay as caterpillars all the time. When it is time, they make chrysalis around them and stay inside it until they are ready to come out as a butterfly.

16. Most caterpillars are nocturnal.

They do not make themselves available during the day by hiding among the plants.  That is one way of protecting themselves from daytime predators.

17. It is impossible to determine if a caterpillar is a male or a female.

It is because they are not fully developed yet. Their reproductive organs start to develop when they are inside a pupa. This also means that caterpillars do not mate or reproduce.

18. Caterpillars cause damage like many other pests.

Once they get into a garden, they are like unstoppable eating machines. Caterpillars are in this stage for one mission only, and that is eating and gaining mass. However, their selfishness causes unbearable damages for farmers.

19. Caterpillars have 6 eyes (ocelli) but none of them see anything except lights.

The main thing is quality, not a quantity. We can relate that saying with caterpillar eyes. Those six eyes are unable to form an image, only they can help caterpillars to differentiate the light from darkness.

20. Caterpillars have 3,350 more muscles than humans do.

Caterpillars have more than 4000 muscles. Humans got only 650.

By Arslan Batyrovich

Founder of
Writer, Researcher, Fact-finder, and All-in-one
Loves nature, Likes history, and Adores anything interesting
To get tailored writing or to work with, contact at [email protected]

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