All insects have six legs that are mainly used for walking, but they are also useful for jumping, hunting, swimming or digging burrows. All adult insects have three body parts: the head, the thorax and the abdomen. Insects also have a pair of antennae and two pairs of wings.
Some smaller animals, such as spiders and centipedes, are often mistaken for insects. Spiders and centipedes are actually arthropods or invertebrate animals with four pairs or more of jointed legs. Like insects, they also have an exoskeleton or a hard, shell-like outer skeleton. Their three body parts are segmented into a series of repeated modules. Unlike insects, arthropods cannot fly.