To become a butterfly, a caterpillar first digests itself

If you were to cut open a cocoon or chrysalis at just the right time, caterpillar liquid would ooze out.

But not all the contents of the pupa dissolve. Certain highly organized groups of cells known as imaginal discs survive the digestive process.

These discs use the protein-rich liquid all around them to rapidly divide the cells needed to form the wings, antennae, legs, eyes, and all the other features of an adult butterfly or moth.