How do I take care of little boys?

I agree with the above poster- be all about fun and laughs and jokes and having a good time, but if things get out of hand then turn to the serious mode and say, "Guys, let's knock it off. We can't be fighting here." or something like that. Once everyone is back on track then you can become the fun guy again. Boys this age like to push the boundaries a little but it's not typically out of being bad or mean. They are just hyper-interested in physical stuff and talking about who is stronger than whom etc. And they LOVE immature humor, even if it's a little bit low brow, that's okay!