Using sound to hunt for food is a pretty ingenious adaptation for bats flying at night. But it doesn't work if another bat is messing with you. Scientists have discovered that a species of bats can purposely jam the sonars of others to keep rivals away from their insect prey.
Aaron Corcoran, now at Johns Hopkins University, was studying bats in Mexico when he noticed some odd behaviour in Mexican high-tailed bats. As scientists do, he set up a high-speed camera and several microphones to figure out what was going on. He found that when the Mexican high-tailed bat swoops in on an insect, it emits a "feeding buzz" entirely distinct from echolocation. Bats will sometimes accidentally jam each other while echolocating and simply switch to a difference frequency, but this feeding buzz can jam echolocation pings in any frequency. It seemed very deliberate.
So far, this jamming behaviour has been observed in only one species of bats. But a moth can also jam the sonar of bats to avoid being eaten. All of this is too high-pitched for our human ears, of course, which is probably a good thing. [Science]