1. Why do they “run” in their sleep?Sigma S/Shutterstock
As you may have guessed, this usually means they’re dreaming, and fortunately, it’s not usually of any medical significance, says Gary Richter, DVM, integrative veterinarian, and veterinary health expert at Rover.com. What’s interesting is that studies revealed certain dog breeds acted out their hallmark traits while dreaming, like an English springer spaniel flushing out prey or a pointer “pointing” in its sleep. If all that “running” during sleep seems excessive, Dr. Richter says it could point to underlying stress or a medical condition.
2. Why do they bark at the window?Carol Kelpin/Shutterstock
Every day the mail carrier delivers mail, your dog barks. Does this dog behavior simply mean dogs hate mail carriers? “Barking at people outside is a protective behavior. Dogs see their house as their territory and anyone approaching or near their territory is a potential threat, so they bark to ward off the intruder,” says Dr. Richter. Adding to it, each time the mail carrier delivers mail, your dog barks and the mail carrier goes away. It creates a pattern that is reinforced over and over. “From the dog’s perspective, they are saving the house from invasion every day by driving away the invader. We never appreciate their efforts,” says Dr. Richter.
3. Why do they roll in stinky things?Robert Petrovic/Shutterstock
Dogs have upwards of 300 million olfactory receptors in their nose, and humans have a paltry six million. With all those receptors, you would think dogs’ high scent orientation would steer them away from vile and pungent smells, like dead animals, yet it’s like Eau de Stinky to them. “Their opinions about what constitutes an attractive scent are often different from ours,” says veterinarian Jennifer L. Summerfield, Brown Veterinary Service, DVM, CPDT-KA. “It’s thought that the behavior of rolling in dead or especially stinky things may have originated as a way of disguising the dog’s scent, which could be useful for hunting.”
4. Why do they eat gross things?Phil Stev/Shutterstock
Like smell, a dog’s sense of taste is vastly different from ours. We both like a juicy burger, but dogs find a rotting chicken or even vomit quite tasty, too. “Dogs originally evolved as scavengers eating scraps on the periphery of human settlements, and feral dog populations today still manage to survive quite well on less-than-ideal food sources like trash, roadkill, and other unsavory options,” explains Dr. Summerfield. But why don’t they get sick when they eat nasty roadkill or expired food? “A dog’s GI tract can process bacteria and other contaminants that would make a human sick and is often able to extract some nutritional value from ‘gross’ things like poop or vomit.”
5. Why do they search for the perfect pooping place?Dora Zett/Shutterstock
Dr. Summerfield says there are three possible reasons for this. One theory is they are stamping down the grass for a clean place to poop. The second is they are scanning the area for predators before they go. Lastly, a study found the most interesting reason. “A study done in Europe found that dogs tend to align themselves in a North-South position when they poop,” says Dr. Summerfield. Even more fascinating, dogs rarely relieved themselves along the east-west alignment.
6. Why do they sniff your crotch?Photick/Shutterstock
You really don’t have to apologize to your new friend when your dog sniffs their crotch—but you will anyway. Dr. Summerfield says the reason why you shouldn’t be embarrassed about this dog behavior is that dogs collect a lot of vital information via their nose and the most concentrated sources of pheromones the crotch or butt area whether you have two legs or four. It doesn’t matter if your human or not. “Although we might find this behavior socially inappropriate, sniffing the anus or genital areas of another dog is a very polite and normal way to say hello in the canine world—much like shaking hands for humans,” says Dr. Summerfield. “So it’s not surprising that when they’re meeting a new human friend, many dogs go straight for the crotch for a good ‘getting to know you’ sniff.”
7. Why are they aggressive to some dogs and scared of others?alexei_tm/Shutterstock
“Many dogs are anxious or uncomfortable about interacting with other dogs—this can be due to genetics, negative past experiences, or a lack of adequate early socialization as a puppy,” says Dr. Summerfield. A dog may lunge forward and bark at another dog to keep it from getting to close; other dogs may hide or cower behind you while some just lay down in an overly submissive posture because they’re fearful or not comfortable with the situation. Dr. Summerfield adds, “It’s not uncommon for a dog to be wary of other dogs, but very friendly towards humans—or vice versa.”
8. Why do dogs lick toes (and other body parts?)photo-oxser/Shutterstock
Let’s start with the most licked place: our face. “Licking the face, especially around the mouth, is a normal friendly greeting behavior that dogs often display towards other dogs when saying hello. This is usually seen a submissive gesture—a way of saying, ‘Hi there! I’m no threat to you!’” says Dr. Summerfield. So, it’s perfectly natural for a dog to lick a human face too. As far as feet, fingers, and in between toes: The stronger the smell, the higher the attraction. “This may be due to the higher concentration of scent in these areas, which is also why many dogs are attracted to dirty socks and dirty laundry.”
9. Why do dogs scoot on their butt?Patryk Kosmider/Shutterstock
The butt scootin’ boogie is kind of comical to watch, but you have to wonder why they do it and what they are leaving behind on your floor. It’s a sure sign of plugged or infected anal glands.”Normally, these sacs express their contents, a very pungent-smelling brown fluid, when the dog defecates. But occasionally, the sacs might become plugged or infected and have a hard time emptying on their own,” says Dr. Summerfield. To relieve the discomfort, they scoot their butt on the floor. “If this happens, your veterinarian can normally resolve the problem by expressing the glands manually.”
10. Why do they stash things?Candy299/Shutterstock
Some dogs bury their treasures while others stash them behind a chair or under a stack of pillows on the sofa. Dr. Richter says this is purely instinctual behavior. “They are keeping track of their stuff,” he says. To keep their treasures from being stolen by another animal, they hide it for safekeeping. While this dog behavior is perfectly natural, some breeds known for hunting like hounds and terriers are prone to digging and hiding as the prey they hunt lives underground. Dachshunds, another breed known for stashing, may have a cache of toys and treats nestled in the corner of a dog bed.