1. Your skin is your largest organ. In an average adult, it has an area of 2 square metres and weighs roughly 5 kilograms.
2. There's an awful lot going on inside of it.
3. The technical term for skin peeling is "desquamation".
4. The average person has about 3 million sweat glands.
5. But only *some* sweat glands secrete "milky sweat" that encourages bacteria to grow and make you smelly.
6. Spots and blackheads happen when pores in your skin become clogged with sebum (oily stuff that comes from sebaceous glands) and dead skin.
7. The thickness of your outer layer of skin varies hugely and is as thin as 0.05 millimetres on your eyelids.
8. You continuously shed skin and replace it with new cells.
9. A tan is your skin trying to protect itself from more sun damage.
10. There are probably tiny mites living on your skin.
Demodex folliculorum (pictured above) is one of two species of face mites that live on humans. It's probably hanging out in your hair follicles (including in your eyelashes) right now. The other, Demodex brevis, prefers your sebaceous glands. The mites have scales to keep themselves in place on your face, and "pin-like" mouth parts for eating your skin cells and sebum.
In all but the most severe infestations they're not at all harmful. But they're still there.