Echolocation is a technique used by some animals, such as bats and dolphins, to determine the location of different objects in the world around them using sound waves. Animals that use echolocation emit sound waves that bounce off objects around them. From the returning echo the animal can tell the distance, size and even the texture of the objects around them.
Scientists have identified over a thousand species that use echolocation. This includes all toothed whales, most bats and some small mammals.
Using echolocation, animals can navigate their environment (even in total darkness), hunt prey, avoid predators and communicate with each other, in the same way that human-made submarines use SONAR to find their way around in the deep sea.