Insects and Minibeasts

Insects are the most numerous animals on Earth. Scientists have already named over one million different kinds, and many more are still waiting to be discovered. Every single insect, from a tiny ant to a giant beetle, follows the same body plan: six legs, three body sections, and a hard outer covering instead of bones on the inside.

An insect's three body sections each have a job. The head carries the eyes, mouth, and two antennae for smelling and feeling. The middle section, the thorax, is where the six legs and any wings attach. The back section, the abdomen, holds the parts for digesting food and laying eggs. Because their skeleton is on the outside, it is called an exoskeleton — like a suit of armour.

"Minibeasts" is a friendly name for all the small creatures without a backbone that you might find in a garden. Animals without a backbone are called invertebrates. Spiders, worms, snails, centipedes, and woodlice are all minibeasts, but they are NOT insects — a spider has eight legs, a centipede has dozens, and a worm has none at all.

Many insects change shape completely as they grow, in a process called complete metamorphosis: egg, then larva (a caterpillar or grub), then pupa, then adult. Inside the pupa the insect's body is broken down and rebuilt into a totally new form. This is why a wriggling caterpillar can turn into a winged butterfly — one of nature's most astonishing tricks.