Sleeping beauty

When this little guy is well-fed he can sleep for hours. Seriously. I have woken up in the middle of the night in a panic because I've been sleeping for four hours. That is almost unheard of with a newborn. Not that I'm complaining of course. And if I pull him into bed with me (save the chastising, I know it's not recommended) he could (and has) gone even longer. Most nights he eats before bed sometimes between 10 and 11, then will wake up for a night time snack between 3 and 4. The older boys regularly wake me up by 6, but he usually keeps right on sleeping through until 7. If only I could do something to keep the older boys in bed that long. Life would be almost perfect.