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Why Do Caterpillars Turn Into Butterflies?

Clive Williams is an internet researcher and writer on many genres. He has a BSc. Degree in Information Systems.

The caterpillar life cycle.

The caterpillar life cycle.

A caterpillar is the larva of members of the Lepidoptera order. This includes moths and butterflies. Their sole goal is to eat and grow. They need to gain nutrients so that they can undergo metamorphosis to become a butterfly. They have no way of reproducing as caterpillars, which is why they must morph into a butterfly to continue their cycle of life.

As a butterfly, these insects can mate and lay their eggs. They also enjoy the added benefit of being able to travel long distances quickly.

The mourning cloak caterpillar eats specific types of leaves.

The mourning cloak caterpillar eats specific types of leaves.

What Do Caterpillars Eat?

Caterpillars mostly consume plant material such as leaves. Some caterpillars will only eat specific types of leaves. For example, mourning cloak caterpillars will feed on willow, elm, aspen, paper birch, cottonwood, and hackberry.

Caterpillar Lifecycle

Caterpillar Lifecycle

The Life Cycle of a Caterpillar

Here is the life cycle of a caterpillar as it transforms into a butterfly.


Butterflies will typically lay their eggs onto leaves, and they will lay around 100 to 200 of them. These eggs usually hatch within a few weeks. However, some species will have their eggs hatch after a more lengthy period. For example, the mourning cloak butterfly lays its eggs in the spring, and they will hatch in the summer.


The caterpillar is the larva of a butterfly. Caterpillars will spend most of their time searching for food. These larvae will grow through stages called instars. Each stage has the caterpillar moult and expand. The duration of the caterpillar stage will vary by species. For example, the monarch caterpillar will feed for 10 to 14 days.


When the caterpillar is fully grown, it will stop feeding and find a suitable spot where it can pupate. It will fasten itself somewhere and spin a cocoon to transform into a butterfly. The duration of the cocoon stage will vary between species. According to entomologist Jeremy Hemberger, most caterpillar species will spend 5 to 21 days in a cocoon.


After emerging from its cocoon, a butterfly has to spend time inflating its wings with a fluid called hemolymph. Afterwards, it can finally fly. The lifespan of an adult butterfly can vary by species. Some live for a week while others can live for a year.

Do All Caterpillars Turn Into Butterflies?

All caterpillars will transform into something. However, not all of them will turn into butterflies. Some will turn into moths. As part of the Lepidoptera order, the behavior and lifecycle of butterfly caterpillars will be identical to those of moth caterpillars. They will hatch from their eggs, eat leaves, spin a cocoon, and grow into a winged adult. If you see caterpillar, use this guide to potentially identify it and see if it will grow into a butterfly or a moth. In general, moth caterpillars tend to be hairy.

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Capinera, John L. (2008). Encyclopedia of Entomology. Springer Science & Business Media. p. 640.

Klowden, Marc J. (2013). Physiological Systems in Insects. Academic Press. p. 114.

© 2015 Clive Williams


Clive Williams (author) from Jamaica on June 24, 2018:

Ypu are welcome Faith

Faith on June 24, 2018:

Thank you for the informative article... I love butterflies!

Clive Williams (author) from Jamaica on August 20, 2015:

yes, always exploring, butterflies are beautiful. But do you like caterpillars?

Ruby Jean Richert from Southern Illinois on August 20, 2015:

This was interesting. I love butterflies. I have a white butterfly bush in my back yard and a great variety come to feed off the nectar. awesome!!!

Clive Williams (author) from Jamaica on August 18, 2015:

Hello are most welcome

Frank Atanacio from Shelton on August 18, 2015:

thank you for this charming science lesson my friend.. :)

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