You might have seen your cat doing it: he is smelling the butt of another cat, or when he’s on your cat he turns around. Shoving his butt in your face. But why do they do that?
When cats meet each other for the first time (passed the growling and issing), they will smell each others face and neck. In cat-language this means something like ‘hello’. It is something that two cats do when they have never met before. But why exactly the face and neck? That is because (friendly) pheromones are produced in their cheeks. These pheromones have a calming effect on cats.
After smelling each other face and neck, they start smelling each others butt – but only if they feel comfortable doing so. Smelling the butt means something like “How are you doing?”. It is a friendly and polite “handshake” between two cats who know each other. It is often seen in cats who live with each other.
Cats do this because they don’t recognize each other by the way they look, but through scent. Cats have scent glands in their butts, and a sniff can tell a cat everything about the other cat.
your cat is sitting on your lap, and suddenly he turns around and shows you his butt. His tail up in the sky, like he’s expecting something from you.
Cats do this, because a tail up high means “You can trut me, I’m not a threat to you” in cat language.
You can most likely compare the tail up high and combination with the butt-sniffing, with a human kiss on the cheek or a hug as a way of greeting. This doesn’t mean that you have to sniff your cat’s butt, but it’s a friendly gesture between two friends.
A cat who has his tail down, doesn’t want to be sniffed, can be a bit sniff, or just isn’t in the mood.