Playdates are Hell

I have two extra children here today, and I can't believe how hard it is. They are absolutely driving me crazy. One is here because a friend is out of town, and school is out, and she needs someone to cover for her husband for the day. The other is here because 3 is even harder than 4, and this way I can separate them into 2 groups of 2, which I have already had to do several times. All I can say is that I would go absolutely crazy if I had four of my own.