Why are my nipples hard sometimes? Watch
I have a question.
Can anyone explain why nipples get hard and stiff sometimes?
I'm a girl btw.
Nothing to worry about and is just part of the wonder of the human body.
PS: It occurs to me you might be talking from an evolutionary perspective, in which case we should be aware we are dealing with theories. Some theories I'd advance would be: like goosebumps its a hangover from when we were hairier and the body is trying to insulate itself (Cold) and/or a reproductive/sexual purpose hard nipples signify arousal and thus improve the chance of successful mating (Hormones/Arousal) and/or to aid humans breastfeeding infants (Hormones/Friction).