Have you ever wondered why your cat

Have you ever wondered why your cat's eyes have those creepy vertical slits for pupils? A new study suggests the reason may lie in cats' preferred mode of hunting.

Vertical-slit pupils are most common among nocturnal predators that ambush their prey, according to the new research, published today (Aug. 7) in the journal Science Advances. Most likely, this pupil shape provides the sharpest way to gauge distance for a prey-snatching leap, the study found.

The new research doesn't only demystify the housecat, however; it also reveals that the bizarre horizontal, rectangular pupils sported by goats and sheep likely help these prey animals scan the horizon for predators — and watch the terrain when sprinting from danger. Moreover, circular pupils tend to be found on tall, active predators that are awake during the day. (Sound familiar, humans?)