bedtime behavior

my son is 21 months and doesn't fight being put to sleep at his bedtime of 8 o'clock,,,but he doesn't go to sleep.  He plays sometimes for hours. Example it is after eleven and i can here him actually rocking back n forth in bed while chattering to himself. I am big on routine, he wakes up around 9 in the morning....nap around 1, then bed at 8, why does he have this behavior the rocking back n forth concerns me a little also bucking the bed for a good hour sometimes.  
thanks, eviebelle

[boosty]

i think 1pm is too late for a nap. thats why he isnt sleepy at 8. my daughter is turning three. she wakes up at 7:30 am which is good cause they gotta wake up early for school in the future. she takes her nap at 11am and wakes up by 2 the latest. usually by 1. and goes to bed at 7:30pm everynight. mine doesnt fight it either but i hear her awake in her bed a while too. but no longer than an hour. usually will sleep by 8 though. so maybe you should switch the sleep times.