When children would come into my classroom screaming, and spitting at each other, I would send them to different corners of the room, settle the class, do some deep breathing, and when calmness was restored I'd ask. 'What was happening here?"

The first time I asked the question the children would shrug, the shrug meaning, we don't know.

I would then say, That was war.

When two sides fail to listen to each other, when they spit at each other, and stamp their feet, and are not in charge, they are at war.

What happens when people are not in charge?

Eventually we would reach the conclusion that people get hurt, precious time is lost being angry, and it's really not worth it.

As a teacher you only have to go through that exercise ONCE with each class. The seeds of peace are sown, and if ever anger surfaces, all they need is an element of calming down and all is well.