a family of beetles. The body, which may be elongate, cylindrical, flattened, or sometimes oval, measures 1.5–18 mm in length; species living in the USSR measure up to 8 mm. There are approximately 1,500 species, including approximately 80 in the USSR. The beetles live mainly under bark, in passages made by other insects; more rarely they inhabit fungi or decaying vegetable matter. They are predators or saprophages. Predatory species feed on bark beetles, their larvae, and the like. The larvae of some Colydiidae, for example, the genus Both-rideres, are ectoparasites of the larvae of other beetles.