It's four o'clock and a dozen kids are slithering like snakes across the polished gym floor. Others giggle and scream as they run away. The rules of the game say if you're tagged by a snake ...

working with up to 600 kids in Calgary. Others giggle and scream as they run away. The rules of the game say if you're tagged by a snake, you turn into one. The last one standing wins. Each child ...