I recently house-sat for my parents while they went on vacation. Neither of their pets, a 14-year-old cat and an 11-year-old dog, do well being boarded, so it was much less stressful for me to stay with them than it would have been to send them somewhere.

I brought my three dogs with me, so it was a very full household. Their elderly Lab cross, Duke, already knew my two oldest dogs, Layla and Dobby, quite well. However, he wasn’t as familiar with my youngest pup, Mischief. This posed a bit of a problem.

You see, like many dogs, Duke tends to default to humping when he’s stressed or unsure. Any time my dogs would start to play, Duke’s lips would stretch back towards his ears, his brow would furrow, and he would grab Mischief with his front paws, attempting to mount her.

With the 40-pound size difference between the two dogs, this did not make Mischief happy. Being a fairly socially savvy dog, she would spin around to face him when he did this, the doggy version of “Knock that off,” and if that didn’t work she would escalate to snapping at him, saying, “No, really, I mean it.”

Of course, knowing that Duke was likely to hump Mischief when he became anxious or excited, my boyfriend and I were able to prevent this behavior most of the time. When Duke started to circle towards Mischief, we would say his name, redirecting him to move towards us for praise and petting. When we had visitors over and Duke hit his limit of the amount of excitement he could stand before he could no longer make good choices, I put him on leash. If we couldn’t supervise the dogs, one or the other of them was crated.

Humping is a common behavior in dogs and is seen in males and females, whether they are fixed or not. While it is most often attributed to “dominance,” nothing could be further from the truth. Dominance refers to priority access to a resource, and I have yet to see a dog use humping to gain access to food, toys, space, or anything else tangible. So, why do dogs hump? Here are the most common motivations behind humping in dogs:

1. Arousal

Once a dog hits a certain level of excitement, that energy has to go somewhere. Some dogs express their joy by doing “zoomies,” where they tuck their butt and sprint as fast as they can in circles. Some bark. Some hump.

2. Anxiety

Like Duke, most humpers whose owners seek my help are quite anxious. Anxiety leads to arousal, and as we saw above, that leads to humping. Technically, canine behavior experts call this a “displacement” behavior. When the dog becomes anxious, he or she may scratch, sniff, dig, or hump. People display displacement behaviors too (although luckily humping is not usually one of them!): We check our phones, play with our hair, or look at our watch when we’re in socially uncomfortable situations.

3. Play

Play is interesting. When dogs (or other mammals!) play, they mix up a bunch of behaviors in new sequences. These behaviors have very useful roots: chasing, stalking, and pouncing are useful hunting behaviors; mouthing and wrestling are useful fighting behaviors; and humping is a useful sexual behavior. Some biologists believe that play is practice for the real world. By mixing all of these useful behaviors up with some other signals that mean “just kidding,” dogs get a chance to practice moving their bodies in ways that could increase their chances of surviving a situation where the behaviors were needed for real.

4. Status

While this is a common attribution for humping, dogs almost never use humping as a form of status seeking or as a display of status. In fact, in more than ten years of training, I’ve only met one dog who appeared to use humping as a means of status seeking. (And even in that case, the dog was also pretty insecure, so the humping was more likely caused by her anxiety than by her desire to climb the social ladder.)

5. It just feels good

Frankly, dogs just like to hump sometimes. All mammals masturbate, and some dogs will hump a favorite toy or pillow. From a behavioral standpoint, there’s no reason not to let Fido or Fifi have a little “me time” on occasion behind closed doors, as long as it’s not causing problems. Two of my dogs, Dobby and Mischief, often hump each other when they are playing, and as long as both dogs are okay with it, I don’t interrupt them (although I will ask them to take it outside). I draw the line at humping people, and if my dogs do this I redirect them and teach them more appropriate ways to interact with humans.

So there you have it. Humping is a normal doggy behavior, albeit a somewhat embarrassing one for those of us on the other end of the leash. So, tell us your embarrassing doggy stories: Why do you think your dog humps?

More by Sara Reusche:

• Four Things You Should Know About Your Dog’s Growl
• How I Got My Dog to Stop Eating Poop

Sara Reusche, CPDT-KA CVT, runs Paws Abilities Dog Training in Rochester, MN, and writes about dog behavior issues at Paws Abilities.