A few years ago it was found that certain bats emit squeaks and by receiving the echoes they could locate and steer clear of obstacles--or locate flying insects on which they feed.

• 几年以前人们发现某些蝙蝠发出短促的尖叫声,它们利用接收回声就能确定障碍物的位置并绕开它,或者能确定在飞行中的昆虫的位置捕而食之。