Ian likes to jump in his crib and will do it when we promt him by saying, "Bouncy, bouncy, bouncy!" in a voice that is annoying to anyone but a baby. While we were trying to capture it on video Madeleine came in to show off her lovely singing voice. She does a great "Jingle Bells" twice.
If you watched the whole thing (sorry if it was a little long) you saw how Ian was shaking his head back and forth with incredible speed. You may have even noticed my comment about how tired he was that he probably couldn't even see straight. Do your children do this when they are extremely tired? Another thing I have seen him do is hit himself in the face to stay awake. It's kind of funny and kind of sad at the same time.
When does the change occur in us when we decide we would rather let ourselves sleep than do crazy things to stay awake? I guess there is probably still a little of that in most people. Imagine if you were driving and beginning to nod off. You obviously can't let yourself sleep at the wheel so you start hitting yourself in the face or other assorted insane activities to keep yourself conscious. I think I might like to see a video like that.