(hundreds, in 14 subfamilies)|
The family is among the largest of the animal kingdom, with about 40,000 species and considerable variation among them. Common features include a generally dark appearance, possibly iridescent, large head and mandibles, a pronounced marginal ridge on the pronotum, and striate elytra. Sizes range from 0.7 mm up to 66 mm.
Ground beetles are found in all habitats and at up to 5,300 m in the Himalayas. Most are nocturnal predators and scavengers, but some, such as the tiger beetles are active in the daytime, using their eyesight to capture small arthropods.
Several types of ground beetles, in particular the bombardier beetles, are notable for being able to squirt a jet of hot foul-smelling liquid from their abdomens.
When the life cycle is known, it is one year, with adults living for two to four years.