I only wake them up if they are still sleeping at start of afternoon 'snack time' ... prior to that at the end of 'two hour quiet time' the sleep time music is turned off and changed to 'wake up music', the curtains opened and the awake children are allowed to return to their normal voice levels and more active activities on the main floor ~ IMO if a child is still sleeping through all that activity they must still NEED it so I let them go until it impedes of the 'routine of the group' at which time than I will go in and help them with a little prompting.