First, let’s clear something up about recent reports of a live cockroach pulled from a woman’s skull. It was technically in her skull, between her eyes—but if you stick your little finger in your ear, that’s technically in your skull too.

More precisely, the roach had crawled into her sinuses. In a video that has gone viral, the roach is seen wriggling through pink flesh and eventually being pulled live from the Indian woman’s sinuses, after entering her nose while she slept.

M.N. Shankar of Stanley Medical College Hospital in Chennai, India, confirmed to National Geographic in an email that he filmed the extraction, and as far as we can tell, the woman’s plight is real.

This is the stuff of nightmares—the idea that one of the most reviled animals on Earth might slip inside your face at night.

Watch: Cockroaches Survive Squeezing, Smashing, and More

But what kinds of creatures actually climb into people? More importantly, what parts of the body do they get into? And could this happen to you? These are just the kind of gory details I love to dig up for you, curious reader.

Tasty Earwax

Roaches are the most common invaders worldwide. In a period of two years, a South African hospital pulled 24 critters out of people’s ears. Ten were German cockroaches, followed by eight flies, three beetles, a tick, an assassin bug, and a badly mangled moth.

And in 1985, he New England Journal of Medicine reported that one patient came to an emergency room with roaches in both ears—when sprayed with numbing lidocaine, one of the roaches shot out "at a convulsive rate of speed and attempted to escape." (Read more about bug and spider myths.)

“It’s actually not an uncommon phenomenon to have a cockroach in the ear,” says entomologist Coby Schal of North Carolina State University. “The nose is more unusual.”

Why so many roaches? “Roaches are searching for food everywhere,” Schal says. “And earwax might be appealing to them.”

Earwax harbors bacteria that produce compounds called volatile fatty acids. Meat also emanates these compounds, “so a roach could go in to explore and then get stuck,” Schal says. Likewise, nasal secretions might be appealing to a roach hunting for a midnight snack.

Staying Alive

Though they might see your ears as snacking territory, roaches aren’t parasites.

“The roach is not really interested in being on a human, and he wouldn’t be if the human was awake,” Schal notes. That’s why almost all roach invasions happen while the person is asleep.

They also don’t tend to be big. Though the roach in the Indian video seems large, Schal could tell immediately it was young and likely a nymph, or pre-adult form, of Periplaneta, a group that includes the large American cockroach sometimes found in houses. (See "Giant Roaches Can Grow Big Testicles When They Need Them.")

View Images German cockroaches are one of the most common bugs that end up in human orifices. Photograph by Nigel Cattlin, Alamy

Given its small size, Schal says it’s plausible that the roach could have gotten pretty far into the sinuses. The nasal cavity and sinuses are larger than you might think, extending between the eyes and into the cheekbones, and since these are air-filled spaces, an insect can survive in there for a while.

How long? “Maybe one of your readers will volunteer to stuff a roach up their nose and see,” quips entomologist Gwen Pearson, insect education and outreach coordinator at Purdue University. (We were joking; don’t do that.)

The point is, no one really knows, but you’re usually better off with the insect staying alive until you can get to an emergency room for professional extraction, for unpleasant reasons you’ll read soon.

Rectum Invaders

A roach in the nose is not as bad as it gets.

Some leeches are known to enter any orifice they can find, including the eyes, vagina, urethra, or rectum.

In 2010, scientists described a particularly unnerving leech species in Peru with huge teeth and dubbed it Tyranobdella rex, or T. rex. So far it has been found only in nostrils (which is reportedly quite painful), but similar species turn up in other orifices, so it’s probably just a matter of time. Hopefully there won’t be a video.

View Images The T. rex leech has large teeth (not shown) that emerge when sawing into flesh. Photograph courtesy Plos One

Apart from intestinal parasites, few species brave the human rectum. Flies are not picky, though, and will invade and consume human flesh by laying eggs that hatch into maggots. And that’s a common enough problem that there’s a medical term for maggot infestation: myiasis, reported throughout human history, including in the eyes and rectum. One particularly detailed report in 1783 describes a Jamaican surgeon’s attempts to remove maggots from a patient’s nose using everything from rum to powdered mercury blown up the man’s nostrils.

Other insects might get there by accident, as in the cockroach that turned up in a 52-year-old American woman’s colon during a routine colonoscopy. She had a roach infestation at home, and doctors suspected she somehow swallowed it whole. Endoscopies, they note, have also turned up ants, ladybugs, yellow jackets, and wasps (ouch).

Keep Calm

If you feel the panic mounting, don't worry. If an insect does crawl into your nose or ear, the worst thing that can happen is an infection (rarely, it can spread from the sinuses to the brain).

Though people think of roaches as dirty and covered in bacteria, they actually groom themselves constantly, Schal says. Your biggest risk is crushing the roach while trying to remove it, releasing the copious bacteria in its gut—that can lead to an infection. (For more on the positive side of roaches, learn why cockroaches made it onto our list of all-star animal dads.)

And in most places, the odds of waking up with an insect inside you are slim. Reports are most common in the tropics, where there are more insects, and in cases of severe insect infestations in the home.

Lastly, don’t believe every horror story you see online. “I see so many fake videos of spiders in people’s skin,” says Purdue's Pearson.

A bogus report that a spider climbed into a man's appendectomy scar, for instance, made the rounds online, but spiders don’t burrow into wounds, and certainly can’t climb around under your skin.

Your best chance of keeping insects out of you is to eliminate infestations in your house, for instance by making sure food is put away and secured, and keeping food out of the bedroom.