J.K.
Well, I can relate - I have two boys, 5 and 8 who have spent the better part of last year at each other's throats. They seem to be in a good groove now which leads to me to believe that these things go in cycles (though that cycle may seem like forever). A few years ago, I read this book called Mom, Jason's Breathing on Me, The Solution to Sibling Bickering by Anthony Wolf which really helped me. He suggests that if they aren't bothering YOU (eg really really loud) or seriously injuring each other, you stay out of it. If one of them comes to you and complains, you either say "do you need a hug" and don't offer advice or tell them to work it out between themsleves. This has been my technique though I find myself occasionally getting involved. But, truly, my kids do get along better when I stay out if it more. The two things I have realized are that these kids have different personalities, they are forced to live in a house together and they need to learn how to work things out amongst themselves. As long as no one is getting hurt physically or mentally, I'd say stop getting involved with it...try to learn to ignore it a little bit more.