Our bodies have two main kinds of sweat glands. The sweat glands that are distributed over most of the body produce an innocent, clear sweat that's more than ninety-nine percent water. As this watery sweat rinses your skin, it cools the body by evaporationand even performs a community service by rinsing away potentially stinky bacteria!
Why So Smelly?
But there's another type of sweat gland located only in the armpits, groin, and around the nipples. These sweat glands produce a thicker, cloudier sweat that's a favorite food of certain bacteria. And once these sweat-loving bacteria really start chowing down, they make the smell of the sweat on these parts of the body even stronger. That's why the longer you're sweaty, the stinkier you get.
Like the first type of sweat glands which cool and cleanse the body, these stinkier sweat glands also have an evolutionary function. For other mammals, this potent sweat speaks volumes about an individual's identity and level of sexual interest. But does it still serve the same social purpose for humans? In fact, there is some evidence that it does.