How do bats use the Doppler effect?

Answer 1

A bat can tell how big an insect is based on the intensity of the echo. A smaller object will reflect less of the sound wave, and so will produce a less intense echo.The­ bat can sense in which direction the insect is moving based on the pitch of the echo. If the insect is moving away from the bat, the returning echo will have a lower pitch than the original sound, while the echo from an insect moving toward the bat will have a higher pitch. This difference is due to the Doppler effect

Answer 2

Bats use the Doppler effect by emitting high-frequency sound waves while flying. When these sound waves bounce off objects in their path, the frequency of the returning echo changes based on the object's motion relative to the bat. Bats detect these changes in frequency to gauge the distance, speed, and direction of objects in their surroundings.