Bombardier Beetles Defend Themselves by Spraying Hot Liquid from Their Behinds

Bombardier beetles are found in various parts of the world – in fact, they’re found in all continents save Antarctica. And these beetles live up to their tough-sounding name by defending themselves in the most unique of ways – by combusting internally and releasing boiling, noxious liquid from their abdomens, aimed at their attackers.

A research team from the Massachusetts Institute of Technology, University of Arizona, and Brookhaven National Laboratory was able to discover how bombardier beetles produce the boiling chemical concoction and are able to emerge from it without any physical damage or injury. The liquid created is called benzoquinone, which, according to the researchers, is a common defensive chemical produced by insects. But bombardier beetles up the ante, so to say, by heating up the chemical to near-boiling temperatures, and shooting it from their behinds in jet streams of hot and noxious liquid.

The team noted that the beetles mix two chemical precursors in a protective chamber located in their behinds. The materials then combine to create the noxious solution, and as that happens, bombardier beetles give off intense heat, bringing the liquid close to boiling point, and helping them generate enough pressure to release the liquid in jet streams. But how durable is this protective chamber? According to the researchers, the reaction chamber “possesses a rigid, reinforcing structure to minimize stretching and sustain temperature increases during an explosion,” while other parts of the beetle facilitate controlled and reversible stretching to allow it to control the streams of liquid.

Findings of the study team were published earlier this week on the journal Science.