Quiet Critters live in a soundproof jar and only come out when it's quiet. Put one of each child's desk when they're being quiet and when they begin to get noisy place the critter to the side of their desk as a warning. If they continue to make noise the critters hide back inside the jar. The children who still have critters on their desk at the end of the lesson replace them with a sticker or alternative incentive ! Brilliant!