You're covered in mites—and yes, that’s mostly normal. You’re not alone in your own skin; millions of tiny inhabitants share it with you.
Our skin hosts entire micro-ecosystems. Bacteria and fungi grab most of the spotlight, but mites are part of the mix too. Among the most common are demodex mites—tiny eight-legged relatives of spiders—that nest in hair follicles and pores, especially on the face. Nearly every adult carries them.
They’re not intruders. Scientists commonly describe them as symbionts—organisms that live with us as part of a shared biological system. They feed on skin oils and dead cells, spend most of their lives tucked inside pores, and emerge at night to move across the skin, mate, and lay eggs.
In practice, most people never notice them.
In the latest episode of the Strange Health podcast, we investigate what these microscopic companions actually do on our bodies and why the idea of them can feel unsettling. If mites are normal, when do they become a problem?
To explore this, we spoke with Alejandra Perotti, professor of invertebrate biology at the University of Reading, who studies how mites relate to humans.
Perotti emphasizes that simply having mites isn’t a sign that something has gone wrong. Human skin isn’t a sterile barrier; it’s a habitat. That balance can shift, though. In some individuals, demodex populations can surge, particularly when the immune system is compromised or the skin barrier is disrupted.
This uptick has been linked to conditions such as rosacea and blepharitis, which can cause redness, irritation, and inflamed eyelids. Even then, the mites themselves may not be the primary cause—the symptoms can stem from the immune response to them or to microbes associated with them.
Other mites live with us in different ways. Dust mites, for example, inhabit bedding, clothing, and carpets, feeding on fungi that grow on shed skin. They don’t bite, but their waste products can trigger allergic reactions in some people, contributing to asthma, eczema, and hay fever symptoms.
Then there are mites that cause disease. Scabies is caused by a species that burrows into the skin to lay eggs, triggering intense itching and inflammation. Cases have risen in parts of Britain and Europe, especially where people live in close contact—care homes, schools, and student housing.
Despite its reputation, scabies isn’t about cleanliness. It spreads through prolonged skin-to-skin contact and is treatable with prescription creams and coordinated treatment of close contacts. The stigma attached to it often causes more distress than the condition itself.
Head lice are often tossed into the same conversation, but they aren’t mites at all. They’re insects that spread through head-to-head contact and are common among children, regardless of hygiene.
So why does the idea of mites provoke such a visceral reaction? Partly because they trigger our disgust response, an evolutionary tool that helped us avoid disease. That instinct can blur the line between normal biology and genuine medical issues.
The reality is less dramatic: humans are ecosystems, not solitary organisms. Most microscopic life on our skin is harmless or beneficial. Only a small number of species cause disease, and when that happens, it’s a medical concern, not a moral failing.
Listen to Strange Health to learn which mites are simply part of everyday biology, which ones cause real problems, and why understanding them matters more than fearing them.
Strange Health is hosted by Katie Edwards and Dan Baumgardt. The executive producer is Gemma Ware, with video and sound editing by Sikander Khan. Artwork by Alice Mason.
You can listen to Strange Health on major apps, via the RSS feed, or learn other listening options here. A transcript is available through Apple Podcasts or Spotify.
Katie Edwards and Dan Baumgardt are the contributors quoted, with their affiliations noted in the article. This piece is republished from The Conversation under a Creative Commons license; read the original for the full context.
