HOW BATS USE SOUND:
People cannot usually hear bats, though sometimes they can, but not very well.
Bats “call” or “shout” at very high frequencies (called ultrasound) which is generally beyond what people can hear.
Bats use these calls like a sort of radar, in that they shout and use the echoes which come back to “see” their surroundings and hunt for food — this is called “Echo locating”
Bats are not “blind” they can still see with their eyes.
Bats echo-locate by producing and projecting ultrasonic sounds from their mouths or (in the case of Horseshoe Bats, through their noses) and then detecting the echoes that return from any solid object within range.
Bats produce these pulses in rapid succession in order to receive a regularly updated picture of their environment.
Thus a single call provides a bat with a single snapshot of its environment whereas a series of calls provides a series of snapshots, rather like looking at a single photo compared to a movie film.
How do bats manage to interpret the information? - This depends on how they call and it is explained on the next page.