Terminal Phase Feeding Call of the Hawaiian Hoary Bat
When bats detect an insect from returned echolocation calls they rapidly increase the pulse rate and raise the frequency of calls in order to gather more information on the insect including location. These calls emitted right before a bat closes in on an insect are called terminal phase calls or "feeding buzzes". The frequency is well above human hearing capabilities at 65 khz and bats will emit some 200 calls per second.
Location Taken: HI, US