dd has been biting ALOT lately. Its usually when ds has a toy she wants but sometimes it just so he will get away from her. Ive tried time out, spaking, making her bite herself, biting her lightly myself just about everything and it does not sink in. Shes leaving bruises on him its rediculious. Its not like she just does it when I have my backed turned she does it infront of us too. How in the world do I stop this?