They differ from other animals in that they have three body parts, a head, thorax, and abdomen, on which are found three pairs of jointed legs. The insects have external mouth parts and are covered by a tough, waterproof exoskeleton. Most have wings. In the entire world, there are about one and a half million animal species described. Of this number, about one million are insects.
Insects are bees, beetles, and butterflies.
They are froghoppers, firebrats, and flies. They are also midges, moths, and mayflies. And there are more, so many more. Insects can be found in every type of habitat. From the Arctic to the Antarctic, treehole to tree canopy they occupy every land niche.