When the echoes come back from the prey, such as a fly, the sound pulses increase to more than 25 per second. This gives the bat a better idea of where the fly is moving. This method of navigation is very efficient for the bats. Some insects, like gnats are so small that they weigh almost nothing. So some bats may catch more than 1200 insects in an hour, or one insect every 3 seconds.
Some bats are so good at echolocation that they can detect and avoid wires as thin as human hairs.