Many animals, including dogs, cats and various species of monkeys, will move their ears to better focus their attention on a novel sound. Asking children to 'prick up their ears' means asking them to listen intently.

Can human ears prick?

The team discovered this ability by measuring electrical signals in the muscles of the vestigial motor system in the human ear. ... The results have now been published in the journal eLife.

Why does a dog prick up its ear?

A dog's hearing is extraordinarily sensitive and even though they can hear more than four times better than humans, they'll turn their ears toward a distant sound so they can pick it up even better. Often they'll perk their ears straight up so their earlobes don't interfere with the audio reception.