Crazy?

So I have a dilema. A love hate relationship with my children and the summer. I truly love my kids, yet I find that this summer, (it does seem much worse this year than before) they are driving me absolutly, up the wall, crazy. I feel like all the work I do is undone, (I have 5 kids so that is no small feet) And the bickering this year seems unprecidented. I am not sure why it has escalated to this. Tonight I sent all my kids to bed at 7:30pm and its JUNE. Translation 30 minute later betime. With this much fighting I figured they must be tired, right? So here I am, so tired of their poor behavior that they all were down 30 minutes before the normal time. Much to my relief my home is now quiet. They are helpful kids, they are loving children, they can be quite charming and polite-here's the catch- When they WANT TO BE! I can't make it happen more than that. I find I am unsure of this new ground I am on. Usually, I feel pretty unflappable. I can roll with the kids, I'm tired by bedtime, but so are they. And this year they have me exhausted by 3pm! I love all my Babies, but right now I feel like I could post some on ebay, and come away ok with that thought! (Just kidding, I would never sell the darlings) So any hints to deal with chores, or bickering dilemas are welcome!!