My girls keep biting each other and I don't know what to do. I say " no bite" and pull them away but I don't always catch them in time. They do it when they are angry like if one is trying to take the others toy. Its been a few weeks and I have had them bite me so I know it hurts like hell & leaves bad marks. Is this just a phase I have to get through or does anyone have any other tips to make them stop?