Bombardier beetles have special glands inside their abdomens that produce a mixture of chemicals. When they sense danger, they release these chemicals in a rapid reaction. The mixture gets extremely hot, reaching temperatures close to boiling, and it creates a loud popping sound and a burst of noxious gas. This explosion scares away predators like spiders, frogs, and even other insects.
What makes this defense mechanism even more incredible is that bombardier beetles can aim their chemical blasts with incredible accuracy. They can turn their bodies and shoot the chemicals in any direction, giving them a great advantage in escaping from danger.