My stepson comes and stays with us on occasion but doesn't live at our house full time, so when he does come and stay our Rott is very dominate over him. He has growled when Justin (my stepson) goes by his dish even just walking by it. When ever Justin goes into the kitchen where Hercules's food is, Hercules runs in there and puts his head over his food dish to protect his food. If my stepson goes to leave him out and reaches for his collar Hercules will back away from him. And put Justin's hand in his mouth (he doesn't bite him he just puts his hand in his mouth. Any advice on what to do??