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.

• 几年前，人们发现有些蝙蝠会发出尖叫，通过接收回声，它们可以清楚的避开障碍物，并定位她们捕食的昆虫。