You’re not alone on your skin—and that’s not as creepy as it sounds. In fact, it’s completely normal. Your skin is a bustling metropolis of microscopic life, hosting entire ecosystems that include bacteria, fungi, and yes, mites. But here’s where it gets fascinating: among these tiny tenants are demodex mites, eight-legged relatives of spiders that call your hair follicles and pores home, especially on your face. Almost every adult carries them, yet most people never even notice their presence. But why does the idea of these microscopic housemates make us squirm? And this is the part most people miss: they’re not invaders—they’re symbionts, living alongside us as part of a shared biological system. They feast on skin oils and dead cells, spending their days tucked away in pores and emerging at night to roam and mate. So, when do these mites become a problem? That’s where things get controversial.
In the latest episode of Strange Health, we dive into the world of these tiny creatures and why our instinctive disgust might be misplaced. We spoke with Alejandra Perotti, a professor of invertebrate biology at the University of Reading, who explains that human skin isn’t a sterile barrier—it’s a thriving habitat. But balance is key. In some cases, demodex populations can surge, particularly if the immune system is weakened or the skin barrier is compromised. This has been linked to conditions like rosacea and blepharitis, causing redness, irritation, and inflamed eyelids. But here’s the twist: the mites themselves might not be the culprits—it could be our immune response to them or the microbes they carry.
Other mites have different roles in our lives. Dust mites, for instance, live in bedding, clothing, and carpets, feeding on fungi that grow on shed skin. They don’t bite, but their waste can trigger allergies, contributing to asthma, eczema, and hay fever. Then there are disease-causing mites, like the ones responsible for scabies, which burrow into the skin to lay eggs, causing intense itching and inflammation. Scabies outbreaks have been on the rise in parts of Britain and Europe, particularly in crowded settings like care homes and schools. But here’s the part that challenges stigma: scabies has nothing to do with cleanliness—it spreads through prolonged skin-to-skin contact and is treatable with prescribed creams. The stigma attached to it often causes more distress than the condition itself.
Head lice, often lumped into this conversation, aren’t mites at all—they’re insects that spread through head-to-head contact, common among children regardless of hygiene. So, why do mites provoke such a visceral reaction? Partly because they trigger our disgust response, an evolutionary mechanism to avoid disease. But this instinct can blur the line between normal biology and genuine medical issues.
The reality is less alarming: humans are ecosystems, not solitary organisms. Most microscopic life on our skin is harmless or even beneficial. Only a small number of species cause disease, and when they do, it’s a medical issue, not a moral one. But here’s the question we leave you with: Should we fear these microscopic housemates, or embrace them as part of our natural biology? Listen to Strange Health to explore which mites are harmless, which ones cause real problems, and why understanding them matters more than fearing them.
Strange Health is hosted by Katie Edwards and Dan Baumgardt, with executive producer Gemma Ware. Video and sound editing for this episode by Sikander Khan, and artwork by Alice Mason. Tune in via your favorite podcast app, download directly via our RSS feed, or find out how else to listen. A transcript is available on Apple Podcasts or Spotify.
Now, we want to hear from you: Does knowing these mites are normal change how you feel about them? Or does the idea still make your skin crawl? Let us know in the comments!
