Bombardier Beetle

Bombardier Beetle, a name given to several species of beetles, of the genera Brachinus and Aptinus, in the sub-family Carabidae. The name refers to their offensive and defensive habit of discharging an acrid volatile fluid with explosive force from the abdomen. Some ants and other insects exhibit the same curious protective device. The discharge has a pungent odour, acid and caustic properties, and evaporates with effervescence in the air. These beetles are usually found under stones or at tree roots, often in great companies. The larger and more brilliant species are tropical. Several small species of Brachinus are natives of England. The most common English species is only about four lines long. When roughly handled, it will make more than a dozen discharges in rapid succession.