These mites have sex on your face while you sleep

There’s a microscopic mite has sex on your face while you sleep. And its penis is on its back.  

Yep, you read that right. While you’re busy dreaming, these eight-legged mites are getting busy with each other. 

This mite is the Demodex Folliculorum. They live inside the pores of our skin and use the oils produced by our skin to ‘fuel their all night mating sessions’. Impressive. Since they can’t protect themselves from UV radiation, they hide inside our pores during the day and come out at night for food and sex. 

They’re almost big enough to be seen by the human eye, at around 0.3mm. And apparently, having these mites is actually a good thing – they help keep our pores unblocked and free of the oils that can cause skin problems. How kind of them.  

Around 90% of the population has Demodex mites – they are thought to be passed from mother to child during breastfeeding. Apparently, though, aside from this transmission from mother to child, these mites stay on the same person forever. So no, your mites and those of your partner won’t get along as well as you do. This means that these Demodex mites inbreed for over 1200 generations, until their ‘host’ dies.  

But there’s an issue. This incredibly isolated experience means that that these mites are approaching what researchers describe as an ‘evolutionary dead end’. Demodex are protected from the challenges of the outside world because they live inside the pores of our skin. Because they’re pretty sheltered from natural selection processes in their oily homes, it’s actually resulted in changes to their genes – for example, having body parts growing in different ways – one of which is their penis, which now grows out of their back.  

Since these mites don’t tend to go out and party with mites from other people’s bodies, they pass on the same genes over millions of years. They also stop passing on the ones that aren’t necessary, like melatonin, which they can instead get from the glands on our skin, making them increasingly dependent on us for their survival. At some point, the gene pool will get so small that they’ll become extinct.  

Until then, the next time you look in the mirror and appreciate your glowing skin, send a little note of thanks to the Demodex who are working so hard (albeit unintentionally) to keep your pores clear.  

Make sure to subscribe to our newsletter if you want to read more blog posts like this one.