Bats are the only mammals that can really fly. Perfect for living in the dark. Its eyes are almost useless. By emitting ultrasonic waves, it can distinguish objects according to the echoes reflected by them. When flying, the nose and mouth will emit an ultrasonic wave that humans can't hear, and will bounce back when encountering insects. After the bat receives it with its ears, it knows the specific location of its prey and catches it.
The frequency of sound it can hear can reach 300 kHz/ sec, while the frequency of human is generally below 14 kHz/ sec. Bats with echolocation ability can produce short and high-frequency sound pulses, which will be reflected when they meet nearby objects.
Bats can determine the location and size of prey and obstacles when they hear the reflected echoes. This skill requires a close combination of highly sensitive ears and vocal centers with auditory pathways. Individual bats can also communicate with each other in the form of sound pulses. A few bats rely on smell and vision to find food.