Reading Comprehension (RC) | Insect-eating bats rely heavily on echolocation, a method of sensory p

Insect-eating bats rely heavily on echolocation, a method of sensory perception by which certain animals orient themselves to their surroundings, detect obstacles, communicate with others, and find food. While using echolocation, these bats emit a series of short, high-frequency sounds from their mouths or nostrils that bounce off objects and surfaces and then return to the animals’ ears. Since high-frequency waves do not diffract, or bend, extensively, these ultrasonic vibrations provide bats with accurate maps of their surroundings. The biosonar of some bats is so advanced that it allows them to fly in complete darkness, snatch moving insects out of the air, or hover just above water level to drink.

For years, scientists have been aware that bats emit slightly different frequencies in differing situations. Recent research has provided insight into how certain physical features help bats use this variability to differentiate among objects in their environments. Many species of bats have elaborate, intricately shaped flaps, or noseleaves, around their nostrils that are adorned with grooves and spikes. Three-dimensional computer simulations of these noseleaves revealed that furrows along the top of the noseleaves act as cavities that resonate strongly with certain frequencies of sound. As a result, the grooves cause different frequencies of sound to discharge in different directions. Lower frequency sounds are spread more vertically, while higher frequency sounds emit more horizontally. The complexity the noseleaves add to the bats’ ultrasound perception could help the bats perform difficult tasks, such as locating prey while avoiding obstacles.