Border collies are herders, bred hundreds of years ago to work with sheep, Pilley said. If a farmer's dog didn't listen to the farmer, the farmer didn't breed the dog.

Good Dog: Border Collie Learns More Than 1,000 Words. January 11, 2011 3:55 PM ET. Eyder Peralta A border collie named Chaser has attained the vocabulary of a 3-year-old child, ...