Both of my boys were biters at this age. I think they just need to grow out of it. Constant reprimand for biting helps them not do it...and to be honest, giving them a gentle bite back helps them understand that it does not feel bad. My youngest used that as his retaliation for everything. But he didnt start bting until he went to an in-home daycare for about 4 weeks. The little boy who lived there is a very physical little boy, a year older than mine, and constantly hit and kicked him. My son would bite back and I let him do it then. The parents never told their son no, and me telling him did no good. But I would tell him NO firmly, and sometimes even put my finger on his mouth and tell him no. Biting is not okay, but it is normal for this age group. I hope he stops soon, for your sanity, because I know how frustraing it is!