Dear Lara,

Sometimes I get an overwhelming urge to rub my face on things I love—like my microscope. Other times I’m so happy to see my tortoiseshell roommate that we bump our heads together.

I talked about why I do that with my friend Dr. Jessica Bell. She’s a veterinarian at Washington State University.

She told me that cats rub their cheeks on things when they’re happy or want to say that thing belongs to them.

“There are scent glands in their cheeks,” Bell said. “The glands release a happy or low-stress pheromone. So, they use it to mark all the places they’re most comfortable or happy. It can be their owner. It can be the doorway. It can be where their food dish is.”

Scent glands make and release chemical messages. Some chemical messages are used by members of the same species to communicate with each other. They’re called pheromones.

Cats have scent glands near their tails, on their bellies, and in between their toes. When a kitten kneads on its mother’s belly while drinking milk, that releases pheromones. When a cat scratches on a scratching post or your couch, that releases pheromones, too.

Cats also have scent glands all over their faces—near their cheeks, lips and foreheads. Those scent glands release five different pheromones called feline facial pheromones. Their main purpose is marking territory. The cat is saying, “This is my place. I feel happy here.” Or “This is a human I like.”

Photo: Hisashi/Wikicommons

Some scent marking behaviors are so common that scientists give them names. Remember how my roommate and I bump our heads together when we’re happy to see each other? That’s called bunting. It’s like a high five, a hug and a chat all in one. Allorubbing is when two cats rub their pelts against each other.

Scientists even make artificial feline facial pheromones that you can spray or diffuse into the air. It’s like putting up a sign that says, “It’s ok. This place is safe.”

“We use pheromones on our blankets and kennels in the veterinary clinic,” Bell said. “We sometimes use it in our exam rooms to help reduce the overall stress load on the cat—or how they interpret the stress.”

Cats pick up pheromones using their noses and special sacs on the roof of the mouth called the vomeronasal organ. It’s part of the cat’s smelling system. It connects to the cat’s brain and works like a scent analyzer.

Have you ever seen a cat grimace? It opens its mouth and pulls back its lips while lifting its head and tongue. That’s called Flehmen’s response. Cats do it when they smell something interesting. It’s like taking a big sniff with your mouth.

Lots of animals have vomeronasal organs like cats do, including elephants, snakes and turtles. Most humans do, too. But whether that organ picks up human pheromones or no longer functions at all is still a mystery.

Maybe someday a clever cat like you will sniff out the answer.

Sincerely,

Dr. Universe