Once there were three little girls, Kathy, Lilly and Susan. They were all new to my school in the seventh grade and had come from different schools. But in eighth grade, when they were together, they turned themselves into a gang that was mean to other kids with increasing frequency and ferocity. Teachers knew it was happening, but the girls were clever and slippery. We could rarely catch them in a teachable moment or a punishable act. The most we could do was talk to them. As you can imagine, that didn’t change anything.