One reason we love dogs is they give us so, so many reasons to feel superior to them. But much of what they do is so bizarre and unfathomable that you can't help but wonder what the hell they're thinking.
It turns out they have their reasons. Weird, disgusting reasons.
Look, this is the elephant in the room. If we're going to talk about strange dog behavior, and don't get the "they eat shit" thing off the table right away, we would be shouted down until we addressed it. And rightfully so.
Dogs eat their own poop, they eat other dogs poop, mother dogs eat the pups' poop (your mom never loved you enough to do that, did she?). They'd eat poop all day if you let them.
So What the Hell Are They Thinking?
Back when dogs were wild and roaming the plains instead of riding around inside of tiny purses, predators could find a dog's den by detecting the smell of poop, specifically the kind left by defenseless, tasty puppies. Puppy feces has a distinct smell (you puppy owners know this!) because of the high milk content, making it the shit equivalent of a Swiss delicacy. So, to clean up the evidence and keep predators away, mom would eat it. We don't know why she doesn't just bury it, but we're not here to judge.
Only imagine that stick is poop.
Anyway, this tradition carries on even for dogs that had been living in the comfort of human homes for generations. Tradition just works like that sometimes, you don't know why you and your buddies high-five when you're celebrating something, you just do it because that's what people do. You would think that at some point you'd reevaluate it if instead of slapping hands you were fucking eating your own shit. But again, they're dogs.
And on that subject, explanations for poop eating outside of cleaning up for pups includes boredom (imagine being so bored that eating your own shit seems like a fun way to kill a few minutes--do your dog a favor and toss a stick it) and just general cleanliness. That last one is especially true if the dog is in a confined spot in the yard or in a pin, because leaving it just laying out, well that would be gross, wouldn't it?
5Sniffing Each Other's Asses
"Dear Cracked.com article on weird dog behavior. I noticed that when meeting another dog, Rex frantically sniffs the other dog's anus, while the other dog returns the favor in a kind of Yin-Yang of ass sniffing. Worse, sometimes when a person comes to the door, he'll do the same to them! How much more savage should the beatings become to cull this disrespect?"
So What the Hell Are They Thinking?
Just as each human has a unique face, each dog has a unique ass stank. If you've ever wondered why dogs sniff each other's asses on meeting, wonder no more. They don't need to see a face, just smell an ass.
"Get me as many pictures of dogs sniffing asses as you can find!"-Cracked Editorial Staff.
It's not, however, because they want to smell the dried shit and fart residue around there. Dogs have two glands around their anus, and sacs that emit a fluid. That stuff tells another dog everything they need to know; the dog's sex, how healthy they are, what their diet is like, even their mood.
If you think we're exaggerating, keep in mind a dog's sense of smell is 100,000 times more sensitive than a human's. To them, there's a whole autobiography written out in that other dog's asshole.
"Oh, so you're originally from Memphis, OK."
By the way, those glands are also why dogs drag their butts on the floor. Under normal conditions when a dog poops, the force of the shat is supposed to empty its anal sacs. However, some breeds (usually smaller dogs) cannot empty the sacs and they become impacted and irritated.
You can have a vet or dog groomer squeeze that stuff out of there or, if you're the adventurous type and not opposed to getting knuckle deep in dog sphincter, there are do-it-yourself guides available. Since the difficulty of this task on eHow is "moderately easy," we'll assume they've never had to reach up a backwoods and homophobic bloodhound's anus.