Thysanurans are wingless insects that have changed little since the Devonian, retaining a body plan that resembles the earliest insect fossils. They are covered in fine scales that give them a metallic sheen and slide off easily in a predator's grip, which helps them escape.

Most species live in soil, leaf litter, or under bark, but a few thrive in human structures and feed on starch in book bindings, wallpaper paste, and stored grain. Females lay eggs over a long adult life that can extend for several years, far longer than most insects.