The Mites That Get Busy On Your Face All Night Long

By Heather Ramsey on Monday, June 8, 2015
Haarbalgmilbe
“Sex: the thing that takes up the least amount of time and causes the most amount of trouble.” —John Barrymore

In A Nutshell

We’re told to avoid or remove ticks that embed themselves into our skin and cause all kinds of diseases, such as Lyme disease and Rocky Mountain spotted fever. But almost every adult human has microscopic mites living in our hair follicles, feeding on the oils our bodies produce. Using their eight legs, they climb out at night to have sex on our faces. However, we’re not the only animals that have microscopic creatures living on us. Legless symbions live on the mouths of Norway lobsters, and larval flukes infect the eyes of freshwater fish.

The Whole Bushel

We’re told to avoid or remove ticks that embed themselves into our skin and cause all kinds of diseases, such as Lyme disease and Rocky Mountain spotted fever. But almost every adult human has microscopic mites living in our hair follicles, feeding on the oils our bodies produce. As far as we know, we can’t do anything about them. By one estimate, the average adult harbors between 1.5 to 2.5 million of these creatures on his or her body, with most on the face. The largest concentrations are around our eyebrows, eyelashes, hairline, and nose. But the location varies by person.

Out of over 48,000 mite species, only two live on our faces: Demodex folliculorum and Demodex brevis. At least, that’s what we believe today. Even though we discovered these mites in 1842, we still don’t know much about them. “These are things that live on us—they’re intimately associated with us—but they’ve not really been studied,” says mite researcher Holly Menninger. “It’s kind of crazy.”

In fact, they’ve lived on us for so long that our immune system generally doesn’t react to them. There is one possible exception, though, that has to do with the lack of anuses on these creatures. Rather than defecate, these mites accumulate their feces within their bodies until they die. As they decompose, their feces are expelled from their bodies all at once, which may cause rosacea to flare up in people with sensitive immune systems.

Every ethnic group that’s been studied has hair follicle mites, from Australian aborigines to white Europeans. However, they’re rarely found on babies. By age 18, about 70 percent of people sampled had them. By adulthood, 99.9 percent of us have mites. We’re not sure how we get them. Two theories are through breastfeeding and sexual activity.

These mites are a lot like ticks and spiders. Using their eight stubby legs to climb out of our hair follicles, the mites crawl around at night and have sex on our faces. Then the females go back into our follicles to lay eggs during the day. Each mite has a palpus on each side of its mouth that claws into our follicle cells. If you want to see the mites for yourself, you have to open your pores during the day. Scientists suggest placing mineral oil on the pores around your nose, then scraping away some of the oil with a small spatula. You may be able to see the mites’ wormy bodies under a microscope, unless your mite population lives elsewhere on your face.

However, we’re not the only animals that have creepy microscopic critters living on us. Legless symbions attach themselves to the mouths of Norway lobsters. Only half a millimeter long, a symbion looks like bloated tube with a hairy ring on one end. The hairs on the symbion push leftovers from the lobster’s food into this tiny creature’s digestive tract. Whatever it can’t digest is expelled through its anus. Up to hundreds of symbions can live on one lobster’s mouth.

Freshwater fish have it even worse. In their larval stage, flukes, which are parasitic flatworms, infect the eyes of these fish. “The lens seems to be the host’s Achilles’ heel,” says scientist Sean Locke. “An immune response there would blind the fish, so it appears evolution has favored immunological restraint. The parasites there haven’t needed to specialize in dealing with any one host’s immune response and hence the same parasite species appear in all sorts of different fish.” The ability to identify these parasites may provide biologists with an initial step to eventually controlling them.

Show Me The Proof

Featured photo via Wikipedia
Centers for Disease Control and Prevention: Tickborne Diseases
Vox: Don’t freak out, but there are thousands of mites living all over your face
National Geographic: You Almost Certainly Have Mites On Your Face
New Scientist: Zoologger: The most bizarre life story on Earth?
ScienceDaily: Freshwater fish eyes: Great home for parasites