A caterpillar sheds its skin several times before it becomes a chrysalis.

The longer version

Growing larvae face a problem because their outer covering is fairly rigid and stretches little. Each time the body fills out, the old skin splits and is worked off, revealing a softer layer beneath that expands before hardening again. Counting the discarded skins is one way observers estimate how far development has gone.

The stages between these moults are separated by periods of heavy feeding, since leaf material supplies the raw building blocks for tissue. Hormones control when a moult happens, and toward the end of the sequence the balance shifts so the final stage produces a pupa rather than another feeding caterpillar.

Where this entry sits

This collection gathers small wonders from the world of ants, bees, butterflies, beetles, and spiders. Expect surprising details about swarms, silk, and metamorphosis, plus the strange everyday abilities of creatures small enough to fit on a fingertip. The full list sits on the Insects and Spiders page, where every entry is listed in order.