Hawk moths may be jamming bat sonar signals by rubbing their genitals.

The behaviour, reported in Biology Letters on 3 July, creates an ultrasonic noise that could be used to scare off an attacking bat and to jam the bat's sonar.

Radar jamming is a common tool in human warfare, clearing the way for aircraft to bomb enemy targets without detection. By flooding the radar frequency with noise, an attacker can render radar useless. A radar operator can resist by switching frequencies randomly, but modern attack techniques, reported to have been used by Israel during a 2007 attack on Syria, bypasses traditional "jamming" altogether and straight-up hacks the enemy radar.

A similar arms race has been going on in the natural world between bats, which rely on ultrasonic echolocation -- or sonar -- to "see", and some species of moths, which have developed special bat-detecting ears and, as this latest study shows, techniques to counter a bat's sonar.