Biting can be a serious and upsetting problem when it happens frequently and over long periods of time. Parents get especially upset when they see those teeth marks on their child's body! It is important to provide first aid immediately after a bite occurs (See page 89 of the Child Care Health Handbook or contact your public health nurse), and then identify ways to prevent the behavior from happening again.
You say you've tried everything. This means that you have checked the classroom environment to see that the curriculum is developmentally appropriate, varied and interesting to the children. The noise level is not overwhelming; there is quiet space, room to move and a minimal number of transitions. The teachers understand the special needs of the toddler age group and are able to address those needs.
Toddlers who are frequent biters need special attention that begins with close observation. Are the "biters" less talkative, less able to use language? Do they walk around with little focus, have trouble concentrating even for brief time periods? Do they play best with sensory material and still put non-food items in their mouths? Noticing these things can help teachers make the best plan for biting prevention.
Children who have little language can practice alternative ways of communicating. Help them to take another child's hand or pull on a shirtsleeve to replace the biting behavior. Practice with situations that might cause biting. For example when there is a toy they want or others move into their space.
Providers often end up "shadowing" a biter in the hopes of preventing bites. As you shadow, talk to the child about their friend's activities and how they might participate. When they make a move to bite, rather than calling attention to the biting behavior, show them alternative behavior for reaching their goal. Praise them for following through.
Help children with especially short attention spans spend more time in play by joining the play and adding new ideas and observations. Add more sensory activity to the class including material that can be "bitten" like infant teethers.
If the behavior does not improve after all these efforts, then it's time to give us a call! For help with biting issues, call 206-296-2770 and ask to speak with your public health nurse.
Greenspan, Stanley I., M.D. and Serena Wieder, Ph.D. (1977). The Child with Special Needs. Boulder CO: Perseus Books.