Ground Beetle, common name for swift-running, often carnivorous beetles. More than 20,000 species are known, of which more than 2500 are found in North America. Ground beetles are worldwide in distribution and live under rocks or in moist or sandy soil, from which they get their name. Many ground beetles do not fly. On these forms the hind wings are generally atrophied and the wing covers fused along the midline. The slender legs are well developed for swift running. These beetles are most often unmarked black or brown; several species have wing cases that are striped or bordered with metallic blue, green, or bronze. The head of a ground beetle is narrower than its body; long, thin, threadlike antennae jut out from the sides of the head. The mouthparts are adapted for crushing and eating insects, worms, and snails. The largest ground beetles are 2.5 cm (1 in) or more in length. The larvae of ground beetles have well-developed legs and mouthparts, are carnivorous, and live and pupate underground.
Ground beetles are agriculturally important because they destroy such harmful insects as the potato beetle, browntail moth, gypsy moth, cutworm, cankerworm, June beetle, and plum curculio. Few ground beetles are considered harmful; some species feed on seeds, corn, and strawberries.
Scientific classification: Ground beetles make up the family Carabidae of the order Coleoptera.