Bats have wide hairless wings that would dry out in the sun if they flew during the daytime. Some bats eat fruit, many bats eat insects and vampire bats in the tropics feed on the blood of animals.
Bats are good at flying at night because they use sound rather than sight to navigate.
This method of navigation is know as echolocation and it is similar in principle to the sonar that submarines use to navigate the ocean. Bats send pulses of sound through their mouths or noses, and these pulses echo back outlining the objects in the bats flight path. The ears of a bat are large and oddly constructed but they help it to determine where the echoes are coming from. To search for insects a typical bat will sweep an area with sound, sending out 10 beats per second. When the echoes come back from the prey, such as a fly, the sound pulses increase to more than 25 per second.