As humans, it’s perfectly natural to wonder why the heck dogs go around sniffing each others’ butts. What seems like a gross habit is actually an act of chemical communication that allows dogs to familiarize themselves with their puppy peers.

Dog’s superior sense of smell

A dog’s sense of smell is 10,000 to 100,000 times better than ours due to their sizable olfactory membranes. Dogs say hello by taking a sniff similar to how we make eye contact and shake hands when meeting new people.

To the side of a dog’s derriere are anal sacs, which are glands that secrete chemicals and pheromones. Unlike humans, pups contain a second olfactory system called the Jacobson’s Organ, which is designed specifically for chemical communication. This explains why dogs aren’t overwhelmed with the stinky smell of poop when they sniff each other. The same organ is used when dogs sniff fire hydrants, or anywhere else that may contain canine urine.

Why do dogs sniff other dogs butts?

When two dogs meet, they usually walk in circles while observing demeanor and posture. This first step will allow them to determine if it’s safe to sniff. The alpha or more dominant dog will initiate the sniffing while the submissive dog waits their turn. Sometimes, the dominant dog will growl or bark, signaling the end of the smelling sesh. Some dogs are more shy about their personal info and will simply sit down and cover their bums with their tails to reduce the odor they emit. Additionally, smelling rear ends acts as a calming mechanism for your pup. Performing this instinctive act soothes them and serves as a stress reliever.

What can dogs learn about other dogs by sniffing each other?

A dog’s genetics, diet, and the state of their immune system can all impact their “perfume.” These scents can share information, like gender, reproductive status, and clues about health, diet, and emotional state. The chemicals also help your pup to determine if other dogs are strangers or if they’ve met before. Like cyberstalking a first date on social media, this intel helps dogs decide how they should behave. It's how dogs first get to know each other!

Since humans don’t possess any of these olfactory skills, body language is the best way for you to identify how your pup is feeling. To learn more about what they are silently saying to you, check out our body language guide.