Page 78 - Design in Nature

Experiments show that bats are able to easily locate and fly through the passageways in the
walls even in complete darkness.

these sounds, which are inaudible to humans, enables the bat to get a "map"
27
of its environment. That is, the bat's perception of a fly is made possible by
the sounds reflected back to the bat from the fly. An echolocating bat
registers each outgoing sound pulse and compares the originals to returning
echoes. The time lapsed between generating the outgoing sound and

receiving an incoming echo provides an accurate assessment of a target's
distance from the bat. For example, in the experiment where the bat caught
the caterpillar on the floor, the bat perceived the caterpillar and the shape of
the room by emitting high pitch sounds and detecting the reflected signals.
The floor reflected the sounds; hence, the bat determined its distance from
the floor. On the contrary, the caterpillar was about 3/16-inch (0.5 cm) to

3/8-inch (1 cm) closer to the bat than was the ground. In addition, it made
minute moves and this, in turn, changed the reflected frequencies. This way,