Your kids are fighting. There's the crying and the screaming, the hitting and the biting. The wailing ever louder, the appeals for your intervention. You get the feeling most of this outlandish behavior is purely for your benefit, but you don't know what to do about it.
Sometimes it's okay to ignore it. I've found that many times, my kids just want me to validate them or vindicate them. This one is right and that one is wrong. You shouldn't take her toy, but you shouldn't bite her over it. They just want your reaction, looking for their Solomon. But it doesn't have to be you.
Of course, sometimes you have to step in...you don't want anyone getting hurt, and you don't want the tantrums to get carried on too far. That's what the whole time-out, you-being-the-parent thing is all about.
But sometimes they do much better on their own, and the sooner they learn to work out their own issues on their own terms, the sooner peace will reign. Sometimes the outcomes will even surprise you, one sibling will give where you thought the other would. It all equals the same thing, though. The kids learning that they can settle their differences without mommy's help, that they can work things out to their own satisfaction.
And with that comes the slow knowledge that it's easier to do these things without screaming and threatening each other. And when those days come, they are happy days.