Bitting Pre-Schooler

I am having trouble with my almost 3-year-old son. He is really acting up, and I can't figure out how to make him behave. When he moved to the 2-year-old class in day care last year, he began biting others as often as three times a day. The school barely worked with me, although he had a good teacher. Finally, the school asked him to leave.
After staying home for four months, he started a new school and was wonderful for a few weeks. Then he began biting and hitting in the 2-year-old class. I potty-trained him and had him moved to the 3-year-old class. Once more, he did fine for about a week and then the trouble started again. He bites, hits, kicks, calls people stupid and even had a boy in a headlock. He rarely acts like this at home. We use timeouts and take away toys and reinforce when he is good by giving him many things to look forward to. Nothing works for long; he continues to push our buttons, and especially the teachers at his school. He's in danger of being kicked out of this school. What can we do? -- Biting Problem
Answer: Parents of a child who bites someone else should expect to be asked by day-care providers to withdraw their child from a school, as he is hurting other children. Most children younger than 3 typically stop biting once they learn it is not the right way to behave. Your son has not learned how to control himself. Because all your efforts to improve his behavior have failed and your son is close to 3, you should seek help from a professional specializing in changing this type of behavior. Ask your pediatrician for suggestions.
If you talk to the day care and explain that you are seeking help for your son, they might give you a little time to see if the biting and other behaviors can be stopped.