You might not know it, but right now there are very likely to be microscopic mites living on your face. These mites are tiny, so you won’t see them if you look in the mirror. For most of us, these guests are totally harmless and just live off the natural oils produced by our skin. However, they have also been implicated in the skin condition rosacea, which potentially affects as many as 1 in 10 people. We spoke to Fred McMahon, a PhD student at Maynooth University, about the mites and how the bacteria within them may be at the root of rosacea.