With the increased level of activity at the school house, the dog is suffering from a lack of playing time. Springtime at a school house is a busy time, with multiple sporting events and extra-curricular activities that tie up faculty and staff.
It's easy to tell when the dog wants to play, he starts carrying his ball with him. This is the sight that greets me most mornings.
I guess it's time to get the ball from him and roll it down the hall. A guy can do worse on a Sunday morning than playing with a dog.