How Do Bats Ply in the Dark?
A bat can fly in total darkness and yet never bump into anything. The bat has a built-in radar system. As it flies through the dark, it utters a twittering sound that is too high-pitched for us to hear.
Echoes of these sounds bounce back from any nearby object.
Bats emit pulses of very high-frequency sound (inaudible to human ears) at a rate of a few to 200 per second. By listening to these echoes with its big ears, the bat is able to avoid obstacles in its path.
The bat also uses echoes to locate the mosquitoes and other insects it catches and eats. Their echolocation ability is so acute they can avoid obstacles no wider than a piece of thread and capture tiny flying insects even in complete darkness.
It isn’t true that bats are blind. They do depend mainly on their keen ears, but most bats can see in daylight. Bats primarily are nocturnal, although many fly early in the evening, sometime before sunset. Occasionally, especially on warm winter days, they are observed flying during daylight hours.