One of my two adopted sisters (adopted when I was 14, and blood sisters to each other)was like that. It became a byword in our family. By the time she was 2, Jeanie would sleep for a couple of hours then bounce in her crib chortling happily to herself for hours. At naptime she would sleep like 20 minutes and then be raring to go. She is now in her mid50s and seems normal. In other words we all survived. *G*