A couple months ago a little girl that is in my 15 month old son's class started biting him when they would fight over a toy. Now she has stopped this and he has started biting her. It's constant. Every day when I pick them up lately, he's been fighting over toys with her and biting. He only bites that one girl. I don't think there's much I can do at home because he certainly doesn't make the connection from what I tell them at home to at school at this age. But it's so frustrating that I can't stop the situation in anyway. Anyone go through a similar situation and have advice?