Humans, and most other mammals, have just four muscles joining their ears to their head. Bats have more than 20, and they use them to execute a precise series of wiggles, swivels, and twitches.
Humans, and most other mammals, have just four muscles joining their ears to their head. Bats have more than 20, and they use them to execute a precise series of wiggles, swivels, and twitches.