Dr. Jennifer Coates, DVM, who serves on the advisory board for Cat Life Today, told POPSUGAR that when cats rub their faces on humans, they are marking you as part of their group. She explained that cats have glands around their mouth, ears, chin, cheeks, and forehead that produce pheromones. "Pheromones are a means of chemical communication between cats. Feline facial pheromones are used to mark territories," she said.
Dr. Coates said that cats also rub their heads and faces on each other as a form of greeting and to reinforce social boding. "In essence, they are confirming that they are part of the same group and are friends, not rivals," she said.
Dr. Stacy Choczynski Johnson, DVM uses what she knows about cat behavior to help her treat cats in her work. She applies a synthetic version of feline cheek pheromone as "perfume" on her wrists and lab coat when she is in the clinic and says, "My hope is that feline patients see me as an instant friend!"
House cats are not the only felines who use pheromone communication. Dr. Stacy said that you may see large species of cats rubbing up against each other or against parts of their environment that they consider their territory. And if you see a lion at the zoo pull back his lips, they're pulling airborne chemical signals into their mouth across the vomeronasal organ to learn about their environment. This is known as the "flehmen response," and you can see pet cats doing it, too, but since they're smaller, it can be easy to miss.
So how should you respond when your kitty cat pushes their cheek up against you? "Cats generally only rub their faces on people they feel very comfortable with," said Dr. Coates. "Take it as a great honor when a cat rubs their face on you, and give them a gentle head rub in return."