Both DS4 and DD19mo have always required less sleep than all the other kids their ages. When DS was an infant he barely slept during the day. All other babies slept during the day, but he just didn't. He always slept fairly well at night, but required less sleep than typical children. He also seemed bored as an infant. As if he couldn't sleep but wasn't sure what to do since he just didn't have the motor skills to do stuff yet. He now sleeps about 10 hours a night, no nap. My 19mo old sleeps about 11 hours a night, with about an hour nap on a good day. Some days she will sleep a few hours...but usually it is less than an hour. They sleep through the night well so I don't feel like I can complain. When DS was about a year until about 3 1/2 he would wake up in bed very early and would just sing forever until we came to get him. Sometimes he would wake up so early it would be almost an hour. He truly was singing for fun though, wasn't upset in the slightest. Very odd, but cute.