Why is it that?

Why is it that when parents take their children to church, the children act as if possessed by naughty little spirits? A few months ago, we could send Hunter to Sunday School during our service and could hold and cuddle Mason as he slept in our arms. No longer. Now that it's summer, Hunter sits (I use the term "sit" quite loosely) alongside us as I forgot to enroll him in Summer Sunday School (who would have thought you would need to enroll) and Mason has found his voice and has decided that cuddling with mommy and daddy is a very low priority. He laughed quite loudly as he hit Mitch in the face with both hands during church today. He threw his bottle. Etc, etc, etc. He and Hunter have now joined forces and are determined that their parents burn zillions of calories during a forty minute church service and miss most of the sermon because Hunter wants to talk about why they dimmed the lights and how much longer we need to be there. Actually today went better than usual as I was able to coax Hunter into my lap for some snuggling and rocking. I even heard some of the sermon as I cuddled him. I'm not sure if Mitch heard much. He battled Mason's newfound energy and desire for independence. To end- Hunter yelled as we walked out of church today, "WE DID IT!"