Only the janitorial staff is allowed on the lower levels. Kids and adult-shaped children love to throw their trash, loose change, and paper airplanes made from exhibit maps down to the lower level. One could even argue that the caretakers of this area are themselves part of the exhibit. Their instructions are to retrieve such refuse on regular intervals offset based on the cardinal direction their posts occupy. Those who sit along the eastern wall patrol their quadrant every 15 minutes according to clocks synced with each other team. As the eastern team finishes their section, the southern team begins. This rotation, while requiring more staff to be on hand, seems to satisfy each member immensely. An 8 hour day is really just 2 hours of work, after all. Staff are encouraged to bring books, sketch, and play games under their assigned awning.