Nepedia
Back to Discover
Fluent Reader
🧬

Caterpillar

life science Maturity 9-11 Next article →

A caterpillar is the young stage of a butterfly or moth.

Monarch Butterfly Danaus plexippus Vertical Caterpillar 2000px
Monarch Butterfly Danaus plexippus Vertical Caterpillar 2000px

Most people know them as small, crawling creatures that love to eat. They belong to a large group of insects called Lepidoptera. While most caterpillars eat plants, a few are very different. About 1% of them actually eat other insects. Some even eat things like wool or the horns of dead animals.

Pasture day moth caterpillar closeup
Pasture day moth caterpillar closeup

Because they eat so much, they are often called "eating machines."

Growing is a big job for a caterpillar. They have soft bodies that must expand quickly. To do this, they must shed their skin several times. This process is called moulting. Most caterpillars shed their skin four or five times as they get bigger. They grow at an amazing speed. For example, a tobacco hornworm can increase its weight ten-thousandfold in less than twenty days.

Pfurtscheller Table 23
Pfurtscheller Table 23

To help them eat so much, they have a special way of moving ions in their gut. This keeps their energy levels high so they can keep growing.

We have known about these creatures for a very long time. The word "caterpillar" comes from the 16th century. It likely comes from old words meaning "hairy cat."

Acharia stimulea 0795036
Acharia stimulea 0795036

We can even find them in the history of the Earth. Scientists found a fossil of a moth caterpillar in Baltic amber. This fossil belongs to a creature called Eogeometer vadens. It lived during the Eocene epoch about 44 million years ago. Another fossil was found in Lebanese amber from 125 million years ago.

Caterpillars use many clever tricks to stay safe from predators. Some use camouflage to look like leaves or bird droppings.

Geometridae
Geometridae

Others use bright colors to warn animals that they are poisonous. These bright colors are called aposematism. Some caterpillars have stinging hairs called urticating hairs. These hairs can cause skin irritation. Some even have venom glands. The South American silk moth has venom so strong it can cause humans to bleed.

Acharia stimulea 0795036
Acharia stimulea 0795036

Other caterpillars use bad smells or even high-pitched whistles to scare birds.

Caterpillars interact with the world in many interesting ways. Some live in groups to stay safe. Pine processionary caterpillars even link together to form a long train.

Other caterpillars, like the Lycaenid kind, make friends with ants. They give the ants food so the ants will protect them. Some caterpillars are also very helpful to humans. We use certain species to make silk or even as food. However, many others are pests that eat the fruits and plants we grow for food.

hypsipyla
hypsipyla
416 words

Where will your curiosity go next?

Keep exploring at your chosen reading level.

🖼️ Images & Media (21)
File:Euthalia aconthea caterpillar.jpg
Euthalia aconthea caterpillar.jpg
File:Chenille de Grand porte queue (macaon).jpg
Chenille de Grand porte queue (macaon).jpg
File:Monarch Butterfly Danaus plexippus Vertical Caterpillar 2000px.jpg
Monarch Butterfly Danaus plexippus...
File:Caterpillar cocoon.jpg
Caterpillar cocoon.jpg
File:Geometridae.jpg
Geometridae.jpg
File:Pfurtscheller_Table_23.png
Pfurtscheller_Table_23.png
File:Crochets.jpg
Crochets.jpg
File:Craesus septentrionalis.jpg
Craesus septentrionalis.jpg
File:Eogeometer valdens holotype 01.jpg
Eogeometer valdens holotype 01.jpg
File:Acharia stimulea 0795036.jpg
Acharia stimulea 0795036.jpg
File:Hairy caterpillar (Costa Rica).jpg
Hairy caterpillar (Costa Rica).jpg
Anise swallowtail and European paper wasp.webm

+ 9 more

More to explore

🔬 Go deeper

More advanced topics to explore

🪜 Step back

Simpler topics to build understanding

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.