Six crows (乌鸦) have been trained to pick up cigarette butts (烟蒂) and other litter in a historical theme park in France. They are rewarded with a small piece of food if they can put the litter in a trashcan. “The goal is not just to clean up the park, because the visitors are generally careful about keeping things clean,” said Nicolas de Villiers, president of Puy de Fou Park. “The initiative (新措施) can show visitors that nature itself can teach them to care for the environment.”