Ya I can understand biting, that happens and loads of kids go through a biting phase, as long as the teachers know who's doing the biting so they can at least try prevent it, that's totally understandable. The big problem was what happened to his arm, and that makes me question everything. Maybe everything has a reasonable explanation, and maybe I'm over reacting, but I can't take the chance. All the people seem so nice though, it's probably just one person who gets too rough when no-one else is looking, and there's no way to know who it was, and no proof against that person.