20 Things You Didn’t Know About Skin

From Discover.com:

3 The skin releases as much as three gallons of sweat a day in hot weather. The areas that don’t sweat are the nail bed, the margins of the lips, the tip of the penis, and the eardrums.

4 Ooh, that smell: Body odor comes from a second kind of sweat—a fatty secretion produced by the apocrine sweat glands, found mostly around the armpits, genitals, and anus.

5 Yum! The odor is caused by bacteria on the skin eating and digesting those fatty compounds.