The Border Collie is an intense, hardworking, highly energetic dog whose ability to impose his will upon sheep is legendary. In fact, he's so good, he just might impose his will on you, too. He has astounding focus, which is a real plus in the field, but if he's left without a job to do, that focus can be a problem. Still doubt this dog's smarts? Check out Chaser , the Border Collie who learned a thousand words!