D.W.
With certain actions there are penaltys to pay. The other mom response was a start, talking to the teacher and or caregivers for any unusual behavior. 2nd as a rule if they bully time out or even special thing they like can be taken away. Choices would be talk about it or something will be taken away for there behavior. With my own children i ask them to tell me what they are willing to give up and if they can't deciede then i make the choice.