On my home from work I pass a large fenced yard in which lives a beautiful Sheltie. When he is outside and sees a vehicle approaching he is at the near corner of the fence and makes a big spectacle of chasing the vehicle as far as he can run (to the other corner). I have made a point of driving by that yard many a day and sometimes go a regular speed and other times I confuse the poor thing by eitehr slowing down or even coming to a complete stop! The addled look on his face when I stop and he was still running is priceless! He has come to recognize the truck and now only runs at half gallop anticipating that I may stop. We enjoy our little game whenever he is outside!