Teachers should be very aware of the goings-on in their classroom. There can be physical torture or mental torture. Look to see if there is a kid that is never included, is never approached to be a potential partner for a project, is never spoken to during recess… even if they seem ok. they probably are not if no one speaks to them. they can be doing well academically but a kids social life is just as important.
Dont point the kid out or tell the whole class to be nicer to Shloimy or Rochel. That will just make him the object of more teasing or ignoring and wont help. Help the kid but dont make it OBVIOUS… like calling the kid out of class many times (and no one else) to talk to him or her. When making a class project, try to assign groups of two. two kids to work on a part together (one being THE kid and the other is one who he/she might possibly get along with.) Split up cliques and the bully with his/her compadres… 3s dont work because one kid can be left out.