The former name for an order of insects containing the bristletails, silverfish, and firebrats. Its use is now deprecated, although it is still commonly found in popular texts. The silverfish and firebrats are now placed in the order Zygentoma, in the subclass Apterygota. These wingless insects typically have slender bodies with long threadlike antenna and a segmented tail-like extension to the abdomen bordered on either side by the elongated paired cerci. They are mostly detritivores living in litter or under bark, although some species are found in deserts and others are familiar inhabitants of human dwellings. These domestic species feed on food debris, paper, cotton, and similar materials. Bristletails are now placed in the order Archaeognatha. They are mostly nocturnal, feeding on algae, lichens, and other plant material and sheltering in litter or beneath bark during the day. They can spring some distance by arching the thorax and flexing the abdomen.