In most insects that feed by suction the mandibles are modified.
Biting mandibles; second maxillae completely fused.
mandibles being well adapted for the capture of small insect-victims. The larvae are more specialized than those of other Adephaga, the head and prothorax being very large and broad, the succeeding segments slender and incompletely chitinized.
The abdomen is oval, sandy-grey in hue and beset with warts and bristles; the prothorax forms a mobile neck for the large square head, which carries a pair of long and powerful toothed mandibles.
There are about 600 species in the family, the males being usually larger than the females, and remarkable for the size of their mandibles.