What are insects?

Insects are arthropods with six legs and body regions called head, thorax and abdomen.

Body and development

An exoskeleton supports the body and must be shed during growth. Many adults have wings, but not all do. Butterflies may pass through egg, caterpillar, pupa and adult stages of complete metamorphosis; other insects develop differently. Antennae help sense the environment. Insects are highly diverse: bees, beetles, flies, ants and butterflies belong to the class but different orders. Spiders are not insects; they are eight-legged arachnids.

Ecosystems and people

Species can pollinate, decompose matter, hunt, eat plants or feed other animals. Some are agricultural pests or disease vectors, which cannot be generalised to all insects. Life stages may need different food and habitats, so conservation goes beyond counting adults. Habitat diversity and pollutant pressures should be considered together.