Why Do Cats Rub Their Mouths on People?

When two cats say hello, they rub faces to share scents. When Fluffy sees you, he's doing the same thing, or at least trying to. From his perspective, you're a pretty tall cat. Because he can't reach your face from his normal position, he might stand on his hind legs. Jumping onto a countertop or a table is part of his attempt to reach your face.

He is also getting your scent on him, and you might notice him grooming himself shortly after he tells you “Hi.” He's tasting the scent he just picked up from you.

Scents can include chemicals called pheromones. A pheromone is more than just a scent, it's a signal that affects the behavior of whomever is doing the smelling. Pheromones are so powerful that artificial ones can be used to relax and calm a kitty who's stressed out.

Fluffy will mark pretty much everything he considers his, to let other cats know who owns those things. That includes you, signaling to other cats that you're his human.

A kitty's sense of smell develops early, from the moment he senses the smell of his mother when he's just a few days old. When he gets older, he'll mark his own territory and the things in it by leaving pheromones on them.

Essentially, a cat creates a map of his world using his sense of smell. His olfactory system is enhanced by a Jacobson's organ, a small passage from the roof of his mouth to a bank of sensory cells above his upper jaw. If you've ever noticed him crinkling his nose, curling his lip and taking a big whiff, this is called flehmening. It's his attempt to get more scent to the Jacobson's organ.

Fluffy has special glands at the edges of his mouth, his temples and the base of his tail. These glands are where he secretes pheromones. When he rubs his forehead, mouth or flank against you, it's to make sure these scent glands make contact with you. This is why he'll head-butt you, a affectionate gesture that serves as both a greeting and a way to get some contact with his scent glands.