I just had to explain nipples to my three-year-old. Her "What are these?" questions never cease to amaze me.
Since I was asked what I told her, I'll go ahead and post it. She was asking about her own, which are of course different from an adult females. I told her that when she was older she'd have breasts and then when she was like 30 and married and had a baby her breasts would make milk and it would come out of the nipples. After which she proceeded to tell me that she didn't want nipples. I don't necessarily blame her.