Science: Beetle Artillery

The bombardier beetle is an inconspicuous insect that ranges much of the world with calm and self-assurance—and for jood reason. When attacked by a ferocious ant, its natural enemy, the bombardier beetle (Brachinus) merely stands its ground, pushes a flexible tube from its rear end and points it at the enemy. With a small but audible bang, a cloud of acrid vapor envelops the ant, reducing it to paralysis or trembling confusion. Until recently, the bombardier beetle's efficient defensive weapon was pretty much of a mystery. Entomologists thought that it simply squirted out...