But first he builds them, on his bed. Having our double size spare mattress on the floor in his room has been the best thing ever! It makes such a great place for him to jump and tumble and we take naps with him there too. So, one of his latest things is to pile up all the pillows and cushions in our flat and then throw himself on them very dramatically and flop around the place. Endless fun, and luckily, not too many bumps and bruises so far.