How do bats use echolocation to find insects in the dark?

Bats use echolocation—a biological form of sonar—to navigate and hunt in the dark by emitting high-frequency sound pulses and interpreting the returning echoes.123

When hunting insects, bats progress through three distinct phases of pulse output:1

• Search: The bat emits approximately 10 pulses per second to scan its surroundings.1
• Approach: Upon detecting an insect, the bat increases its pulse rate to 25–50 per second and shortens the pulses as it closes the distance.1
• Terminal: During final interception, the bat emits extremely short pulses at a rapid rate of 200 or more per second.1

By analyzing these echoes, bats determine an insect's direction, distance, and velocity. They utilize specialized features, such as large external ears and an acoustically isolated auditory complex, to detect faint returning signals. Furthermore, their nervous system integrates vocal and auditory data in milliseconds, allowing them to distinguish their own echoes from background noise and other bats while moving at high speeds. Some species also use the Doppler effect to track target motion.1