Like the whiskers of dogs, seals, and other animals, feline facial hair isn’t just for decoration. The technical term for whiskers is vibrissae, from the Latin word for vibrate, which tells you a little about what cats use them for.

As Purina explains, each whisker is an extra thick hair with a sensory organ called a proprioceptor on the end of it. That proprioceptor picks up vibrations and air currents around a cat and relays those messages to the brain via nerves in the hair follicle. Not only do air currents change when something moves—when you enter a room, for example, or when a dog approaches on the sidewalk—but their patterns also help a cat judge the size, shape, and distance of stationary objects, like furniture. That way, cats can easily navigate unfamiliar (or dark) environments without having to touch or see every obstacle.

And while it’s not unheard of for a cat to get stuck in a tight spot, it would happen much more often if not for whiskers. According to HowStuffWorks, cats’ whiskers are approximately the same width as their bodies, so they often use them to decide whether they’ll be able to fit through an opening. If your cat pokes its head into a narrow cardboard box and then loses interest in climbing into it, their whiskers may have gotten a little too smashed to justify a full-body mission.

Whiskers can also reveal a lot about a cat’s current mood. If your cat’s whiskers are stiff or pulled back, they might feel threatened or upset. Relaxed whiskers, on the other hand, indicate that your cat is relaxed, too.

How Many Whiskers Do Cats Have?

Though the exact number can vary, most cats have 24 whiskers on their cheeks (12 on each). But it’s not the only place cats have whiskers; less conspicuous ones can be found around their chin, near their ears, above their eyes, and behind their forelegs.

Do Cat Whiskers Grow Back?

Considering how much cats rely on their whiskers, you definitely shouldn’t trim them. But it is normal for whiskers to occasionally fall out on their own, and they will grow back. If your cat seems to be losing more whiskers than normal, it could be caused by an allergic reaction, an infection, or stress. In that case, you should take your cat for a visit to the vet.

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