10 month old DS has just learnt to crawl and we have wood floor in the living room and then laminate in the hallway and kitchen. We have one of those foam play mats in the living room for him but it's a large room with a dining area too so lots of space for him to move around but now he wants to be everywhere I'm just a bit worried about his knees getting sore since I can't just cover the full area. What do others do that have hard floor downstairs?