Why do dogs sniff each other’s butts? To humans the butt-sniffing ritual can seem awkward, but it gives a dog access to a lot of information about a new acquaintance, such as gender, health, and diet. Dogs remember scents too, and the smell can help determine if they’ve met another dog before. A dog’s sense of smell is far superior to a human’s. Sometimes they smell things for fun, and sometimes to learn more about something. Their instincts can lead them to greeting humans the same way. If it becomes a problem, you can train your dog to sit when meeting new people. This is a good habit useful in all sorts of situations, especially when encountering people afraid of dogs.