Bats use sound waves for communication and navigation. They emit supersonic radiation ranging from as low as 200 hertz to as high as 30,000 hertz. The sounds are emitted through the bat’s nostrils or mouth and are aided by a complex flap structure to provide precise directivity to the radiation. Echo returns from the emissions allow a bat to pick out a tiny flying insect some distance ahead. Highly sensitive ears and an ability to maneuver with great agility enables many bats to fly around in a darkened cave, catching insects without fear of collision.