A click can hide the echo a bat needs
A hunting bat builds a picture of nearby space from sound. It sends out brief, high-pitched calls and listens for the echoes that bounce back. The delay and character of an echo help the bat estimate where an insect is and how it is moving.
Some moths can produce clicks in the same ultrasonic range bats use. Those sounds do not form a wall or erase the bat’s call; instead, they add extra signals to the brief listening window when the bat is trying to pick out the moth’s echo. With the returning sound harder to distinguish from the noise, the bat may lose a clean track of its target.
Noise buys a moment to change course
That moment matters most during pursuit. A moth can use it to veer away while the bat is sorting through the sound. The defense is an acoustic version of breaking visual camouflage: the moth does not have to become invisible, only difficult to locate for long enough to escape the next approach.
The bat’s sonar remains useful, and a click does not guarantee the moth will get away. But the exchange makes the hunt a contest of timing as well as hearing: the bat sends a call and waits for its echo, while the moth can answer at just the point when that echo matters.
