Since the time it was posted on Thursday, a viral tweet showing an excited dog experiencing its first snowfall has garnered over 71,000 retweets and 228,000 likes. In the video, posted by now-internet-famous pet owner Jo Ellery, the dog frantically runs back and forth on the street as he experiences his first snowfall. This sight might resonate with many dog owners who have themselves watched in amazement as their pet spontaneously experiences a burst of energy and breaks into an uncontrollable sprint.

The dizzying act is actually something that animal experts refer to as the “zoomies,” or, more technically, “Frenetic Random Activity Periods.” According to animal behaviorist Marc Bekoff, author of the upcoming book Canine Confidential: Why Dogs Do What They Do, what’s happening during these spells is pretty much exactly what it looks like: Your dog is super excited and uses running as a way to express it.

“It’s the same for humans, when you’re wired and you just go off and run around and pace back and forth,” Bekoff tells Inverse.

“The simple answer is, dogs enjoy running here and there frenetically. If they didn’t enjoy it, they wouldn’t do it.”

To both the amusement and worriment of owners, the zoomies seem to happen to dogs in a variety of situations, without rhyme or reason. It can happen when their owners get home, after going to the bathroom, while walking through sand or snow, or after a bath. Here’s how dog trainer Steven Lindsay described the behavior in the Handbook of Applied Dog Behavior and Training, Procedures and Protocols:

The spectacle may cause first-time dog owners to suspect that their dog has momentarily lost its mind. Dogs exhibiting such behavior appear to be possessed by a torrent of spontaneous locomotor impulses. They rush about as though careening around obstacles or fleeing from a nonexistent pursuer closing in from behind. Occasionally, a dog may appear to scramble forward faster than its body can follow, creating a hunched-up appearance as it steers wildly along its frenetic path. As the playful release reaches a climax, the dog may display a wide open-mouthed smile, wedging its ears back.

Zogair the dog has the happy zoomies!

It might make sense that the zoomies are more prevalent in younger, more energetic dogs, but they don’t just happen to puppies, says Bekoff. Like humans of all ages, all dogs occasionally feel hyperactive — and often want to share it with others. In his years observing animal behavior, he’s noticed that dogs will get into these fits when they want to play but no one’s playing with them, or in an attempt to engage other dogs in play.

There’s a lot we still don’t know about the zoomies, Bekoff says, and that’s because there hasn’t been much scientific research conducted in the field. No one has “systematically studied” zoomies to see how the activity changes by age, breed, or environment, he says, so most of what researchers know is based on observation and anecdotal evidence. And while the act seems to be a playful sign, there’s no clear-cut scientific research to prove that the zoomies are entirely positive.

Bekoff, however, has drawn his conclusions from zoomies he has observed in the wild — not from domesticated dogs. The same frenetic behavior occurs in wild coyotes and elk deer, he says, when “it’s safe to play.”

“The signal they’re staying in the wild is, ‘Hey, we’re free to do what we want, there’s no danger around so let’s do it while we can,’” Bekoff says.

Multiple articles online instruct owners on how to stop dogs that launch into the zoomies. Bekoff, however, advises that owners let their dogs run themselves out and not to discourage these very good boys from what’s just playful behavior.

“The vast majority of all zoomies I’ve ever seen are done in fun,” Bekoff says. “Let dogs be dogs and do zoomies to their heart’s content.”