BJ and DD went riding every day, but they always had trouble telling their horses apart. So one day, BJ clipped off a piece of her horse's ear. The next day, DD's horse caught its ear on some barbed wire. The next day, DD cut her horse's tail short, but when they went riding, BJ caught her horse's tail in a bush, so that evening they measured their horses. From that day on, they never had any trouble telling the white horse from the black horse.