A theme park in France called Puy du Fou has some unusual helpers picking up litter—birds. Rooks, which are related to crows, are known for their intelligence. Recently, animal trainers taught six of the birds to fly around the park, pick up trash, and deposit the waste in special bins.

The park’s management hopes the sight of these feathered janitors picking up after people will encourage visitors to be more careful when they toss trash. “The purpose is not to just clean the park, but to educate the people to look after the future of our planet,” says Nicolas de Villiers, the president of Puy du Fou.