To find their way, blind people usually use a stick or dog instead of their eyes. But some blind people use echolocation.
Echolocation involves looking with your ears, like bats do. A bat sends out a high-pitched tone, which we call an ultrasonic sound. That note echoes off nearby objects. By detecting these echoes with their ears, bats are able to work out what their surroundings look like.
People are not capable of making or hearing ultrasonic sounds. But some blind people have learned echolocation by clicking with their tongues and by listening carefully to the echo.
