R.K.
I have found that the best way to deal with "a hitter" (when the child is to young to really understand consequences such as time-out) is to not say a word to the "hitter" at first. Go directly to the "hittee" and comfort them, hold them and ask if they are okay. Allow the "hitter" to see this. Apologize to the child, "I'm sorry Timmy hit you. He was mad, but it is NOT okay for him to hit." Escort the hitter to another area, where he can see the other children but cannot interact with them...his "quiet spot". Calmly explain that you understand that he was feeling mad, but when that happens he is not to hit, but to come to his quiet spot and sit for a few minutes. The next time it happens (and unfortunately it will), do the same thing only do not say a word to the hitter when you escort him to the quiet spot. If you need to sit with him to get him to stay, do it, but do not interact with him. I had a biter... this eventually worked when he realized he would miss out on playing and would not get a reaction from Mommy, either. Whatever you decide to do, I wish you good luck! I know it can be frustrating, but I promise, this too shall pass :)