Although no living bats are completely blind, most bats rely on sounds to find their prey at night. Known as echolocation, ultrasonic sounds are emitted by bats that bounce off of other objects. By hearing these echoes off of objects around them, bats can create an internal map that allows them to navigate and capture food.
Most bats consume insects or small vertebrates that are well-suited to finding with echolocation. Some bats capture numerous small insects while in flight, while others hunt large insects lurking amid the rocks and vegetation. Some bats, primarily native to Africa and Asia, subsist on fruit or pollen rather than insects. Bats that eat fruits and nectar usually use their senses of sight and smell to find their prey, and they may be active before darkness falls.
Bats that rely on echolocation often have flaps and folds of skin attached to their faces. While scientists do not yet understand their function completely, it is likely that these flaps and folds aid in detecting the sounds returned by echolocation. Bats produce their echolocation through their nose or their mouth. In addition to the ultrasonic sounds involved in echolocation, bats also emit a diverse array of sounds that are within the range of human hearing.