See all my kids sleep in the same room in playpens right now. Some will chatt and scream playfully for a very long time which really bugs me but does not prevent from anyone else from falling asleep. When one wakes up mid nap I tell him nap time is not over and he still needs to staty there quietly and let him be. I have not had MAJOR screaming problems yet. Maybe I would seperate them if I letting them cry/scream it out does not work. But I would do it for a few weeks. They can be very persistant so we have to be more persistant and consistant I guess. Before nap time I tell them... It's quiete time and I will see you when nap time is OVER. Ofcourse I go check up but they don't know that ;0)