My dog, Dooley, is three years old. When he's inside and anyone passes on the road in front of our house ('his road') he barks. We live in the country and there are a lot of walkers and kids riding bikes. If he's outside in his kennel and anyone walks on 'his road' he barks until he can't see them anymore. It scares the neighborhood kids and some of the adults. He doesn't bark at vehicles. He doesn't bark unless he sees someone. What can I do to stop him from this bad habit?