'Vestigial' human ear-wiggling muscle actually flexes when we're straining to hear

Expressive bald man with healthy skin shows ability to wiggle ears having fun on light blue background in room extreme closeup.

The little muscles that enable people to wiggle their ears unconsciously flex when we're trying to pick one sound out of a din of noise, a new study finds.

Think about how cats, dogs and certain monkeys twitch their ears in response to new sounds. This instinctive movement isn't just for show; it helps funnel sound toward the animals' eardrums, thereby sharpening their ability to pinpoint and process noise.