These insects are unique among the beetles in having very short wing cases (elytra) that leave most of the abdominal segments exposed. This allows them to flex the abdomen upwards and towards the head in a defensive posture that resembles a scorpion. They cannot sting, however, and instead capture their prey with their mandibles. They vary in size from a few millimeters to 1-2 cm and consume a range of prey, including insect eggs, aphids, and small moth larvae. The larval stages live in the soil and feed on other invertebrates.
Beneficial of the Month material courtesy of NMSU ACES: Pocket Guide to the Beneficial Insects of New Mexico