Sometimes you just have to face the facts, even if they seem rather unpleasant.
Most people use the term habitat without realizing that they are one. Yes, you read right: whether you know it or not, you are a habitat and a home base for ectoparasites.
Ectoparasites are organisms that live on the outside of your body, which makes them only slightly less distasteful to discuss than endoparasites, the ones that live inside of you. But, have courage, and don’t head for the soap just yet, for Mother Nature does nothing without reason, and ectoparasites are not entirely dreadful.
Right now, on your face and just beneath the surface of your skin in your hair follicles and pores, wildlife thrives. You have face mites, and lots of them. Sir Richard Owen discovered them in the 1840s. I guess that he didn’t believe that when it comes to facial fauna, ignorance is bliss.
Face mites are microscopic (about one-quarter of the size of the period at the end of this sentence.) They are arachnids, related to spiders and ticks. With a small head, mouthparts for eating, and a worm-like elongated body, they are especially adapted to nestle into your thin, warm hair follicle or pore.
Two varieties live on your face, Dermodex falliculorum and Dermodex brevis. The former prefers communal life in the hair and pore follicles, while the latter has a solitary existence in the adjacent sebaceous pores. Both species especially relish your eyelids, eyebrows, nose, cheek and forehead. To them this habitat must seem enormous and barren — but very active when you sneeze.
In this case, the truth doesn’t hurt. Face mites generally don’t cause damage, pain or discomfort and as decomposers, they assist in getting rid of your detritus. Only in the very susceptible or those with exceptionally high populations of mites will the problem of demodicidosis (itchy, irritated skin) occur. Take heart; there must be more than 10 mites per follicle to cause this problem.
More is not always better, and in the case of face mites, neither is age. Wisdom aside, a disadvantage to aging is that the older you get, the more face mites you typically have. Research shows that senior citizens are especially burdened with a large population of these creatures.
Most face mites are not terribly mobile, although they can occasionally move between pores and even migrate to another face (moving from a pore neighborhood to a more “high-brow” one.) Typically a mite will spend most of its life face-down in one follicle. In this snug home, it will take care of life’s necessities: eating, resting, and mating.
As detritivores, face mites consume your dead skin cells. Luckily for us, they are very efficient eaters, producing no waste. Perhaps this is the only bright side of their existence — they have no excretory organ and so do not defecate. You can be mite-y thankful for that fact.
Mating usually occurs in the follicle with other face mites. An isolated face mite can also reproduce asexually by parthenogenesis, or virgin birth. In this case, a female mite will produce up to 25 eggs that will mature even though they are unfertilized. The eggs, fertilized or unfertilized, will hatch into miniature adults that will grow and mature and begin the cycle anew in about 2 weeks. Since they move infrequently, a female mite can also mate with her male offspring as necessary.
Death is uneventful: the face mite dies, becomes liquefied and decomposes in the follicles of your face. No fuss, no muss.
A minority of us somehow avoids these tiny cohabitators: perhaps 20 per cent of the human population is mite-free. For those of us not in that 20 per cent, I guess we can think of these creatures as unseen helpers: tiny sanitation workers (or beauticians, if you prefer), taking care of dead skin and other waste that you can’t even see. You may not give a thought to your face’s health on a cellular level, but these mites just might.
Suzan Bellincampi is director of the Felix Neck Wildlife Sanctuary in Edgartown.