I have DS who is 2.5, and for the last 2 weeks he has been totally refusing a nap. He'll go to bed quite happily but will just lie there singing and generally faffing about. I know the nap can't go on forever sob but he seems to really need it, as he's then really tired and struggling to hold it together by 4pm. Do I just keep persisting in the hope it's a blip?