An abandoned Chihuahua weighing just 2.5 pounds (1.1 kilograms) proved herself to be a skilled sheepdog.
Nancy was given to London's Battersea Dogs & Cats Home two years ago as a newborn puppy suffering from a severe skin disease, but after being hand-reared by an employee at the shelter, she is now capable of showing fully-grown sheep who is boss.
Ali Taylor, who works at the shelter and trains rescued Border Collies, adopted Nancy and took her to training sessions on farms in southern England.
"Nancy used to watch all her Border Collie friends herd the sheep, and she seemed very interested in what was going on," Taylor said Tuesday. "One day, I decided to give her a whirl in the ring, and she picked it up straight away."
However, Taylor cautioned that dog owners should not attempt to teach their pets how to herd sheep without "proper supervision from an expert."