My 4 1/2 year old male even barks at the passing motorcycles, cars, planes, geese, etc. on the television. When we walk him, he immediately goes into "herd" mode anytime something approaches him. He chases geese, children, bites the kennel owners. The problem with Border Collies, though, the more you try to wear them out the more they want to do. Our dog even recognizes the voice of Matt Galant, host of Animal Planet's "America's Funniest Animal". He'll run over to view the reflection of the television on the front of the stove and proceed to bark at it. When you have a Border Collie, you learn to live with their idiosyncrisies, and adjust YOUR behavior accordingly.