We all know how powerful body odour can smell on some people,
particularly when its seeping from their armpits. But have you ever
considered that your sweaty pit might be your body's own natural way of
keeping predators at bay?
As MayoClinic explains, BO is caused by bacteria munching away at the secretions coming from the apocrine glands located in your armpits. Besides grossing people out, here's another theory on its purpose, courtesy of i09:
[T]he fact that humans sweat when they get an adrenaline rush, indicates to some that humans might produce stink as a warning signal to cleaner animals. Considering carnivores often smell, and carrion-feeders are used to feeding on things that are actively rotting, it has to be some stench.
We admit, the theory's a bit of a stretch. But if other mammals like skunks can use stink as a natural defense mechanism, who's to say that humans can't either?