Drum on every available surface. Whenever I've had to teach - or even be in the same room as - adolescent boys I've been driven round the bend by this. And if they're not drumming they're rocking on their chairs. If they're not rocking on their chairs they're firing spitballs at each other. If they're not firing spitballs they're testing rulers, pencils, chairbacks to destruction. Nothing within arm's reach is safe.