This is a mite you don’t want to meet. Unlike dust mites, which merely live off the crud of your household and may never set foot on your skin, Sarcoptes scabiei prefers to get much closer to its food source. It also eats skin, but it doesn’t wait for you to shed it. Instead, the mites burrow into the outer layer of epidermis, making tunnels where they can live and lay their eggs. Where they set up housekeeping, they cause intense itching, and the scratching that ensues makes wounds that bacteria can thrive inside. We call the itching and lesions scabies (and related species of mite infesting our furry friends cause mange).
Image: Jens Mattssen, National Veterinary Institute, Uppsala, Sweden