any of about 1,500 species of beetles (insect order Coleoptera) named for their jumping, turning, and tumbling motion when disturbed or caught. These black beetles are small, usually between 3 and 7 mm (0.1 to 0.3 inch) in length, and are most often seen on flowers. They are covered with fine hairs and are humpbacked and wedge-shaped, with a broad anterior end tapering to a pointed abdomen that extends beyond the forewings. The larvae live in and feed on rotten wood and plant stems.