My 13M son is biting. He bit my friend's 1 yr. old last week and has been biting us. I think the reason may be due to teething and trying to get attention. He has a 3 1/2 yr. old sister and may be in competition for attention? How do I handle the biting. I had been moving his mouth away and saying that we don't bite, but today he bit my shoulder and broke the skin so I put him in his crib for a few minutes. Anyone else dealing with this or have suggestions?