Have you ever wondered why dogs sniff each other’s behinds? Or even your own behind? It may seem gross to you, but there are actually very good reasons behind the sniff!

Although dogs may seem almost human-like at times (aka anthropomorphism), they are actually very physiologically different from humans; a dog’s nose is their best asset (no pun intended). A dog has approximately 300 million olfactory sensors in their nose, and the area of the brain which analyzes scents is about 40 times larger than our own. This means a dog’s sense of smell is anywhere from 10,000 to 100,000 times more powerful than ours, depending on breed. For example, a Bulldog cannot smell as well as a Bloodhound, as they have less room for olfactory cells.

But why do they sniff butts? Quite simply, our bodies – dogs and humans – are constantly secreting biological chemicals. Some might equate butt sniffing to a hand shake, but it is actually more like having a conversation. When dogs sniff butts (and genitals), they are smelling pheromones and other biological chemicals for gender, health, and reproductive status. You might even notice male dogs smacking or chattering their jaw after sniffing a female. This is because dogs have an organ in the roof of their mouth called the Jacobson’s organ, and doing so helps to concentrate pheromones in order to sense them more efficiently.

In conclusion, dogs sniff butts in order to learn more about one another. Since they cannot form words, this is the most efficient way.