Cats have a reputation for being antisocial loners, but nearly every cat owner is familiar with the moment a cat walks up and bumps his head against someone's face. This rubbing, often accompanied by purring, is called bunting and, like cats themselves, the reasons behind bunting are at once complex and straightforward.
Cats make no secrets about whether they like each other and a little light head-butting is their equivalent of a handshake. Cats will only bunt cats with whom they have a social relationship. How vigorously they bunt and rub depends on the personality of the cat, but when this behavior is accompanied by purring it is called allorubbing and generally is considered friendly. A vigorous allorubbing might be more like a hug, while a quick nose-bump is like a fist-bump.
Cats are extremely tactile creatures and they like a good head scratching as much as anyone. When a cat butts his head up against you and then tucks it down or turns to the side, he may be looking for a head scratching or some petting. Sometimes cats will bump their sides or backsides against you to tell you where they prefer you to scratch. Whatever he bumps you with, your cat is putting his trust in you.
Cats aren't just extremely tactile, they're also extremely territorial. Apart from you, your cat likely will rub her face, cheeks and chin against pieces of furniture, rugs, and other objects. She is marking them with subtle biological scents to mark her territory. Their cheeks and in particular their chins hold strong scent glands; cats can smell scents roughly 200 times better than people. These scents tell cats where it's safe to go and where trouble may be.
You're Not Just Their Territory
Many people assume that cats only bunt them as a way of marking territory, but scent communication among felines is a complex matter. Cats also use scents to help identify people as part of their colonies and to create a singular, familiar scent that they find comforting. And bunting, especially against your cheek, may be just a measure of affection, like a kiss on the cheek.