What type of frequencies do bats use for their radar?

Bats use ultrasonic frequencies for their radar-like echolocation. These sound frequencies are generally above 20 kilohertz, the upper limit of typical human hearing.

Rather than using electromagnetic radar, bats emit brief sound pulses through the mouth or nose and listen for returning echoes. The timing, direction, and changing frequency of those echoes help a bat locate obstacles, identify prey, and judge how quickly an insect is moving. Higher frequencies produce shorter wavelengths, which can provide useful detail when detecting small targets such as moths and beetles.

Different bat species use different call designs. Some produce frequency-modulated calls that sweep across a range of pitches, while others use more constant-frequency calls, often combined with frequency sweeps. Calls can also change during an attack: as a bat closes in on prey, it emits pulses more rapidly in a sequence sometimes called the feeding buzz.

“Radar” is a convenient comparison, but echolocation is acoustic rather than radio-based. Also, not every bat uses echolocation in exactly the same way; it is especially widespread among insect-eating microbats.