This would make a great procedure (Harry Wong). Count to five or hold up one finger at a time when the class needs to refocus. Discuss what occurs for each number at the beginning of the school year and eventually the reaction will be automatic.
Grade Thoughts: Brain Breaks for the Classroom
Themes for Early Childhood -- A GREAT RESOURCE that explains what themes are and why they're important in early childhood. Links to Fun-A-Day's themes and thematic activities,