Every dusk, we can see groups of bats flying out of their hiding places and dancing in the sky. They are hunting for insects! This "feast" lasts until dawn. During this period, most birds are resting, and only a few nocturnal birds like owls come out to hunt. However, owls rely on their night vision, so do bats have good vision too?
Bats' vision is actually not bad. Except for the fruit bat genus, most large bats rely on vision for orientation. However, small bats and fruit bats mainly rely not on their eyes, but on another skill - echolocation. Bats have special vocal structures in their mouth and nose, which can emit ultrasound that humans can't hear. In other words, these bats are constantly making loud noises, but humans can't hear them. Once these sound waves encounter obstacles, they will be reflected and transmitted to the bats' large ears, where they are analyzed in the brain, allowing the bats to understand the surrounding environment.
However, bats often travel in groups. Would their sound waves interfere with each other? No. Each bat has its own unique sound wave, which not only allows them to accurately identify themselves in the complex sound waves, but also with high precision. They can not only locate their flight route, but also identify whether there are delicious insects ahead. For this reason, moths covered with fine fuzz, which are conducive to absorbing sound waves, can achieve "invisibility" in the bats' detection and avoid being killed by bats. The adaptive evolution of bats and moths is the prototype of contemporary radar and stealth aircraft.
In addition to echolocation, bats can also sense geomagnetism and use magnetic fields to orient themselves. Thanks to these amazing skills, bats can fly freely in the dark night.