"What happened to your hair?" <--this is a popular one
"Your hair is wIIIIIld!"
"You need to do your hair!"
"Is your hair nappy?"
I am not making any of these comments up! Children have actually said these things to me. I usually play like I don't know what they are talking about or ask them a question back mirroring the one they asked me. I don't get upset because I always consider the source of these comments. Children are working with a limited pool of experience. They may not have been exposed to natural hair or even know that they themselves are natural.
No matter the source of the comments, I believe in encouraging children to think before they speak. I learned this concept early on and remember thinking a lot of things as a child that I chose not to say. My mama let me know that I couldn't run around saying whatever I liked. On the other hand, adults (sober and drunk--lol) LOVE my hair!