In my house there's a method to the madness.  Not one I've imposed but one I've observed (at least for this stage in their development).  The boys play hard and loud for 30-45minutes, crash and lay in quiet introspection, they eat, they want to spend time with me, and the cycle begins again.  Knowing the cycle is critical. It makes life so much easier. I pick the down time for study. The up time works best for experiments or outings, and the mommy-time is best for asking questions, answering questions, or just listening.