If you’ve had a dog, you’ve probably wondered what the answer is to this question. Butts are pretty gross, after all. That’s where poop comes out, but then again…dogs love poop.

All kinds of poop, but from what I can tell, mostly cat poop.

So, why is this a pooch’s preferred method of greeting? Dog behaviorists are pretty sure they have the answer, so we can put this one to bed.

Dogs sniff each other’s rears to determine each other’s moods, mostly, though it’s also a way to figure out whether they’ve met before, and a whole other host of things, too.

Dogs are far better than smelling than humans – they have between 100 and 20o million more olfactory receptors in their noses than we do, depending on their breed, and a third of their brains are devoted to processing scent signals.

Dogs also have an area in their snout known as the Jacobson’s organ, which are openings in the roof of the mouth that connect directly to the brain. It does more than smell, though – it does a kind of chemical analysis on the molecules as they filter through.

Using it, they can read gender, mood, and health of the dogs they come across on the street, in the park, wherever.

Dogs have anal sacs near their base of their tails, but it’s not the terrible (to us) smells that attract other dogs to the area. The apocrine glands contain pheromones that allow the Jacobson’s organ to “read” their new acquaintance’s gender, mating status, mood, health, what they prefer to nosh, and more.

Humans have apocrine glands, too, and if you think about where your dog loves to stick her nose, you can probably guess where ours are – our crotches, for one (but also our armpits).

So, when your pooch sticks his nose in your crotch (or a strange dog does the same), they’re not trying to be rude – they’re just trying to get to know you better!

Which, you know, doesn’t make it any less awkward in the moment, but if you think about it, is kind of sweet.

Dogs are amazing, so we should always give them the benefit of the doubt, if you ask me.