Cat licking its mouth.

Getting licked by a kitty feels like a brush with sandpaper. But why?

It’s because little hooked papillae, barb-like “hairs” oriented toward the back of the mouth, cover the top surface of a cat’s tongue. These stiff projections act like the bristles of a brush (or the teeth of a comb) to make grooming an especially productive affair.

It’s also thought that the barbs help do the delicate work of separating flesh from bone when a cat eats his prey, though that seems more likely to be the case for big cats like lions and tigers, whose papillae are significantly more developed.