What Makes Bombardier Beetles Special?
Bombardier beetles are so-called ground beetles in the four groups Brachinini, Paussini, Ozaenini, and Metriini and comprise over 500 species. The group Brachinus is the most common group. Bombardier beetles are amazing creatures. They are so called due to their ferocious ability to defend themselves against predators by shooting a mixture of scalding hot and toxic chemicals from glands in their behinds. This is how their defensive squirting action works. Secreting cells produce hydroquinones and hydrogen peroxide which collect in a bladderlike vessel. This vessel is opened through a muscle-controlled sphincter onto a thick-walled reaction chamber. This chamber is lined with cells secreting catalases and peroxidases. As the contents of the bladder are forced into the reaction chamber, the catalases and peroxidases quickly break the hydrogen peroxide down and catalyze the oxidation of the hydroquinones into p-quinones. This releases free oxygen and generates sufficient heat to bring the
