In what has to be one of the most brilliant self-defense mechanisms ever developed, several species of tropical moths are able to rasp their genitals against their bodies to produce ultrasonic signals that confuse an attacking bat's acoustical targeting system.
Several species of Tiger Moth and Hawk Moth have been found to use this technique, which is thought to serve as a warning for bats to keep their distance as the insects are equipped with dangerous barbed legs they're not afraid to use. But it's also a clever way to jam a bat's <del>radar</del> sonar, or at least momentarily throw them off target giving the moths a few precious seconds to make their escape. Not to mention the effect it has on the Tiger Moth bar scene. [Nature via Popular Science]