My dog,Cole, is just about 2 now. He has just started in the last 6 months or so nipping people,but when they are running etc. Its a herding bite,front teeth,rarely leaves a mark. mostly slobber.The problem I'm having is he did it to a 5 year old and some poeple don't understand what a herding bite to a bite bite is. He listens well but is there a way I can break him of this? He will play for hours with kids and then out of no where he bites.