Bats fly low at the speed of 40 meters per second to catch insects. In the evening, however, they use their hearing to navigate. Bats catch insects with the help of an advanced navigation system known as echolocation. They are known to emit high-frequency ultrasonic waves pitched at 20-100KHz. This is too high for the natural hearing of humans. These sounds get reflected when it hits different objects and reverts to the bats as echoes. This echo enables them to generate a mental map of its surroundings. However, these echo signals may get interrupted in case of snow, rains or heavy winds, but they still manage to catch their prey. When bats fly, they produce ultrasonic waves. Ears of the bats are well-trained and so sensitive, that in addition to getting information of distance of any obstacle, they also get an idea of the nature of reflecting the surface.