Page 77 - Design in Nature

Communication and Target Location Systems 75

was this perception of the bat due to the sense of hearing? Or, was it because
it had night vision?
In order to answer these questions, a second experiment was carried
out. In a corner of the same room a group of caterpillars were placed and
covered under a sheet of newspaper. Once released, the bat did not lose any
time in lifting the newspaper sheet and eating the caterpillars. This proved
that the navigational faculty of the bat has no relationship with the sense of
vision.
Scientists continued with their experiments on bats: a new experiment
was conducted in a long corridor, on one side of which was a bat and on the
other a group of butterflies. In addition, a series of partition walls were
installed perpendicular to the sidewalls. In each partition, there was a single
hole just big enough for the bat to fly through. These holes, however, were
located in a different spot on each partition. That is, the bat had to zigzag its
way through them.
Scientist started their observations as soon as the bat was released into
the pitch darkness of the corridor. When the bat came to the first partition it
located the hole easily and passed right through it. The same was observed
at all partitions: the bat appeared not only to know where the partition was
but also where exactly the hole was. After going through the last hole, the
bat filled its stomach with its catch.
Absolutely stunned by what they observed, the scientists decided to
conduct one last experiment in order to understand the sensitivity of the
bat's perception. The goal this time was to determine the bat's perceptual
limits more clearly. Again, a long tunnel was prepared and steel wires of

3/128-inch (0.6 mm) diametre were hung from ceiling to floor and placed
randomly throughout. Much to the observers' astonishment, the bat
completed its journey without tripping over a single obstacle. This flight
showed that the bat is able to detect obstacles of as little as 3/128-inch (0.6
mm) thickness. The research that followed revealed that the bat's incredible

perceptual faculty is linked to their echolocation system. Bats radiate high
frequency sounds in order to detect objects around them. The reflection of