why do cats sniff each others butts

Cats sniff each other's butts as an important form of communication. The area around a cat's anus contains specialized anal glands that produce unique chemical markers and pheromones. By sniffing these scents, cats gather detailed information about one another, including identity, sexual status, health condition, emotional state, mood, and even recent changes in diet or environment. This behavior serves as a natural greeting and helps cats recognize each other, maintain social bonds, and assess whether another cat is a friend, foe, or potential mate. It is instinctual and vital for feline social interaction, similar to how humans greet with a handshake or a hello.