Video: Is gun play a bad thing? Parents sometimes find it unnerving when they hear shouts of “Bang! Bang!” coming from the top of the staircase and discover their children engaged in full pretend battle.

My four-year-old daughter has a beautiful wooden dollhouse that she got for Christmas last year. She plays with the dolls and furniture inside, but what has been most fascinating are the home upgrades she's added using... trash. A junk-mail catalogue clipping has become the TV. Some old bottle caps are now a backyard obstacle course. A sponge is the jumping castle. A handful of shredded tissues is part of a car wash. She runs around, opening junk drawers (yes, we have plural) and exclaiming, "Oh! This can be the swimming pool! This can be a seesaw! This can be the elevator!"