It's their way of saying "hello".
Dogs smell their own butt and the butts of other dogs as a way to gather information about each other. They have special scent glands in their anal region that produce a unique odor that carries important social and health information. It's a natural behavior for dogs to sniff each other's butts as a form of communication and identification.
Humans don't sniff buts only dogs do that to get to know each other.
because depending on the smell they can identify eachother
It's their from of saying 'Hello' like we shake hands
Dogs rely heavily on their sense of smell to gather information about each other, including their identity, mood, and health. By sniffing each other's butts, dogs can exchange pheromones and other scents to gain a better understanding of one another. It's a natural and instinctual behavior that helps dogs communicate and socialize within their pack.
Most of us have more sophisticated ways of gathering info on other people.
Dogs sniff each others butts because it is their way of saying hello
Two, one in each ear, just like humans do.
Through barking and the sense of smell.
because they are like dogs and they smell them there
they lived off of each others butt meat
I am not sure but I think they smell each others smell