AN ADULT INSECT never grows any larger. It cannot, because it has a hard, external skeleton composed largely of a tough, horny substance called chitin. This "exoskeleton" covers all parts of the body including the legs, feet, eyes, antennae, and even the internal breathing tubes, or tracheae. Young insects must shed all these surfaces, or moult, several times during their lives in order to grow to adult size. Beneath the old, hard skin, a new, soft skeleton forms. The insect takes in extra air to make itself larger and splits the old skin, which falls off. The young stages of many insects are grubs or caterpillars (pp. 24-25), which are quite different from the adults; but these also moult, eventually producing a pupa or chrysalis.

The parts of an insect

What is an insect?

The first insects

Wings and flight

Through an insect's eyes

Touch, smell, and hearing

Legwork

Mouthparts and feeding

Battling beetles

Complete metamorphosis

Incomplete metamorphosis

Beetles

Flies

Butterflies and moths

Bugs

Wasps, bees, and ants

Other insects

Living with plants

Hide and seek

How to avoid being eaten

A watery life

Building a nest

Insect architects

Social ants

Honeybees and hives

Helpful and harmful

Looking at insects

Did you know?

Insect classification

Find out more

Glossary

Index