The bat(or dolphin) makes a sound, which reflects off surrounding objects or enemies. The bat gets the reflected sound. It can then tell where incoming objects are.
The fancy name for echolocation is bio sonar (sorry I just love that name). It is used not just by bats and dolphins, but also shrews, and two cave bird groups, the cave swiftlets and the Oilbird.
Ben Underwood was the first human to use echolocation. Because of this, he could do many things like riding a bike, roller skating, surfing, and many other things.
In case you did not know, Ben Underwood suffered retinal cancer from the age of of 2 and had his eyes removed at 3 years. But, unbelievably, by 5 he had taught himself echolocation. He did this by making clicking sounds with his mouth.
Ben had prosthetic eyes when his real eyes were removed. Prosthetic eyes are fake eyes, like a glass eye. It would be weird if you saw someone with no eyes walking around!
Ben is probably the only one to use echolocation to it’s full potential. Most blind people have to use canes or guide dogs to help them navigate to their destination.
Echolocation isn’t just used by the bats and dolphins, but by some other mammals too. Maybe one time you could try using it!