Muffy's kittens are now 3.5 weeks old. At what age do I need to have a litter box accessible to them? Right now I have them in the front closet, but Muffy's been using the litter box in the laundry room. Should I put a litter box in the closet (it would be a tight fit) or should I move them into the laundry room so they would also have access to the kitchen/dinette? Questions, questions, questions...