Can a snake crawl in your mouth as you sleep? Experts examine the viral video

A horrifying viral video raises questions — and fears — about a "snake" that has gone where no reptile should venture: into a person's mouth.

The story, which remains unconfirmed, goes like this: A woman in Dagestan, a region in Russia, began feeling ill and went to the hospital. There, doctors used a tube to remove a four-foot-long "snake" from her throat. Reports from several news outlets claimed that the serpent had slithered into the woman's mouth while she was sleeping, though they cautioned it was unclear whether the creature was still alive.

Luckily, the medical procedure was recorded — and it's pretty gnarly. Even the doctor removing the uncomfortably long interloper jumps back, alarmed by its length.

But the backstory raises major questions. Like whether it's even possible for a snake to creep inside an unknowing human while she slumbers. Inverse caught up with some herpetologists to set the record straight.

What is really happening in this video?

If the description above isn't detailed enough for you, a final warning — this is a truly disgusting sight to behold. With that, here's the video:

If this made you ask "WTF did I just watch?," you're not alone. We had some questions, so we asked the experts what they think is really happening here.

Toby Hibbitts is a research scientist at Texas A&M who focuses on amphibians and reptiles. His theory? It's a worm, not a snake.

"I think that this is a video of the removal of a parasitic roundworm," Hibbitts tells Inverse.

Based on the size, it's possible it's a member of the genus Ascaris — the world's most common group of parasitic worms, according to the US Centers for Disease Control.

Emily Taylor, professor at California Polytechnic State University, agrees that the beast is more likely a gastrointestinal parasite than a snake.

Still, the grainy video makes it difficult to see exactly what's going on. Luke Linhoff, a conservation biologist at Florida International University, notes that the creature "does appear to be a snake," although it could also be said to resemble an eel, or large parasitic worm.

What kind of snake could this be?

While it seems to be a massive parasitic worm, not a snake, we can't fully rule the snake story out based on blurry video footage. If this really is a snake, it's worth knowing which species are common in this region.

Dagestan is located near the Caspian Sea, and snakes in this region are rich in diversity, Linhoff tells Inverse.

"The area between the Caspian and Black Seas has a huge variety of habitats ranging from high mountains to arid steppe, with many amazing and threatened species," Linhoff says. "With a good picture or high quality video, it would be easy to identify the species."

Records from iNaturalist, a social network and citizen science app, show which types of snakes have been spotted locally. Species include the javelin sand boa, Eurasian blind snake, and red-bellied racer.

Can snakes crawl inside you while you sleep?

Regardless of which snakes are prevalent locally, it's worth asking — can the reported backstory have even taken place?

Because if snakes can crawl down your throat while you sleep, we need to know.

Good news: All three herpetologists have large doubts about that happening. For one, any living person's gag reflex would be bound to kick in.

"It would be very unlikely for a snake of any size, especially a big one, to crawl down into someone's stomach while they are sleeping," Taylor says. "The esophagus is collapsed so it's not as though it's merely a tunnel, and people must actually swallow to move items from the mouth to the stomach."

The researchers agreed that a snake would not have a reason to crawl into someone's mouth in the first place.

"Snakes generally avoid people at all costs. They see you as a large predator or threat and do their best to be elusive," Linhoff says. "If they were interested in heat, they would more likely crawl into your clothes."

If a snake — not a parasitic worm — is really the culprit, it's most likely that the animal was swallowed on purpose. And "even that would be difficult," Taylor points out.

Plus, once inside, lack of oxygen and strong digestive juices would quickly kill the serpent.

"So people needn't worry," Taylor says — "the risk of a snake crawling down your throat is virtually nil."