How Do Creatures Use Echolocation For Guidance?

Some creatures employ the sense of hearing in quite an extraordinary way. They are equipped for echolocation. These animals emit high-frequency sounds and are guided, by listening and responding to rapidly returning echoes as the sounds are reflected by objects. For instance, bottle-nosed dolphins use this method to avoid underwater obstacles.

Among echolocators is a well-known flying mammal—the bat. If you were to release a bat in a completely dark room, it could-fly about without hitting the walls or other objects. This is because the animals emit sound pulses of high frequency; as the sounds strike obstacles, they listen for the echoes. Why, they sometimes send out over 200 pulses a second! By interpreting the messages resulting from these echoes, the creature-charts a safe course.

The bat also uses its astounding guidance system to locate the insects on which it dines. But just how it tells the difference between echoes reflected by obstacles and those returning from potential meals remains a mystery to man. For that matter, certain bats catch their prey right on the obstacle, a leaf.