Entomology taxa

Insects and their allies are the most diverse and numerous groups of animals. They live in all continents and in all habitats, ranging from sea level to mountain tops, from the Equator to the poles. They have adapted to varied ways of living as predators, herbivores, scavengers, and parasites of plants, birds, reptiles, mammals and other invertebrates.

Insects and their allies are mostly terrestrial but have also colonised all freshwater habitats. With remarkable exceptions, the only habitat where insects and their close allies have not been able to thrive is the oceans, although there are a number of species adapted to live in intertidal zones.  Their evolutionary success is mainly due to their relatively small size, a hard and waterproof external skeleton (= exoskeleton), wings in many species, a varied diet, and high rates of reproduction. The exoskeleton is periodically shed and the animal grows before the new exoskeleton hardens. To enable movement, the arthropod body is divided into segments and legs, which are jointed.

Different groups of insects and their allies are separated primarily by their external anatomical features.