Sacred Haven of Debauchery

When one dog greets another with a nose in the derrière, it’s basically getting a brief biography of its new friend, written in scent molecules and pheromones. To the sides of a dog’s butt are pouches called anal sacs; these contain glands which secrete chemicals that can tell a sniffer a lot of information about their owner, like gender, reproductive status, and clues about its health, diet, and even emotional state. It may seem like a strange way to go about it, but butt sniffing is just the canine version of shaking hands and introducing yourself.