- [Narrator] There's a creature scurrying across your face right now. Yes, you, and at some point, maybe
now, maybe in a few days, it's going to find a nice
cozy pore in your skin and lay a single enormous egg. Meet the face mites.
They're smaller than a grain of sand, are a kind of
arachnid like spiders, and they feast on the oil
and cells in your skin, particularly on your oily
nose, cheeks, and forehead. Scientists suspect
they've been living on us since the dawn of humanity
over 200,000 years ago, and today, studies suggest
practically every adult on the planet has thousands of them. Odds are you've been living
with them your whole life. Babies quickly get them from their parents a few days after birth,
and once those face mites are on you, the only
thing they enjoy as much as slurping oil and
nutrients from your pores is having sex all over your face. Afterwards, females burrow deep into your pores where they lay their eggs. The eggs end up in one of two places depending on the species of face mite. The first species, called
Demodex folliculorum, lays its eggs in your hair follicle, while the second prefers nesting
in your sebaceous glands. And in under two weeks, the babies hatch, mate, lay their own eggs and die, leaving behind a pile
of decomposing corpses. Now, you can wash some of this off, but you'll never eradicate them completely because even if you treat
them with antibiotics, they'll return in about six weeks, tops. You'll pick them up from towels, pillows, and your loved ones. Well, that all sounds horrific, but usually face mites are harmless. They only become a
problem when they multiply out of control. This can happen in people with an impaired immune system. It's also been seen in
people with a painful skin condition called rosacea. Normally, you'll have
around one or two mites per square centimeter of skin, but one study found
that people with rosacea had 10 times the normal amount. Believe it or not, in some cases, face mites can be useful. Researchers can actually
study your face mites to learn about your ancestors. You see, most mites often
stay within a community. So over time, they've evolved
into distinct lineages in different geographic
regions, and by comparing their DNA, scientists can
trace how different groups of humans migrated across the world. For example, a study
found that European mites genetically diverged from East Asian mites around 40,000 years ago. That's the same time European
and East Asian humans parted ways. Pretty handy. So when it comes down to
bugs crawling all over you, it could be a lot worse.
