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How Is a Butterfly Formed?

Follow one of nature's most dramatic transformations from a tiny egg to a winged butterfly.

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A butterfly begins life as a tiny egg, usually attached to a leaf. A caterpillar hatches and starts eating so it can grow quickly. As its body gets bigger, it sheds its tight outer skin several times. When it is ready, the caterpillar hangs in a safe place and forms a chrysalis. Inside, its body reorganizes in an extraordinary process called metamorphosis. Wings, long legs, antennae, and a curled feeding tube develop. The adult butterfly finally pushes out, rests while its wings expand and dry, and then takes its first flight.

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Scene by scene

Pause, look closer, and discover the science behind each part of the adventure.

Egg to caterpillarScene 01

01

Egg to caterpillar

A pin-sized egg opens, and out crawls a very hungry caterpillar ready to grow.
Look closer

The caterpillar is the larval stage of a butterfly. Its main job is to eat and store the energy needed for the transformation ahead.

Inside the chrysalisScene 02

02

Inside the chrysalis

The caterpillar forms a chrysalis, where a hidden rebuild begins.
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Special groups of cells guide the development of adult structures such as wings and antennae while much of the larval body is reorganized.

First flightScene 03

03

First flight

A butterfly emerges, pumps fluid into its folded wings, and waits until they are strong enough to fly.
Look closer

New wings are soft and crumpled. The butterfly expands them with a fluid called hemolymph and lets them harden before taking off.

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