Corvids, the family of birds that includes crows, rooks, ravens and magpies, are remarkably intelligent creatures. They have been known use tools, plan for the future, and recognize faces so well that they hold grudges against humans who have slighted them. Now, as the Agence France-Presse reports, a theme park in France is putting corvid bird brains to practical—if somewhat humble—use by deploying a team of rooks to collect discarded trash.

Staff at Puy du Fou park, which is known for its history-themed shows and attractions, have taught six rooks that were raised in captivity to pick up pieces of garbage and place them inside a box that releases a treat each time rubbish is deposited. Boubou, Bamboo, Bill, Black, Bricole and Baco, as the rooks are called, are expected to start their new gig this week.

The birds were trained by Christophe Gaborit, project manager at the park’s “Academy of Falconry.” According to Camila Domonoske of NPR, the garbage collection idea stemmed from the park’s falconry show, which sees trained crows pick up roses and bring them to a “princess” in a castle. Gaborit got to wondering if he would be able to teach rooks to perform a similar, albeit less glamorous task: picking up cigarette butts and other pieces of trash and depositing them into a box.

As a Puy du Fou blog post explains, Gaborit started to train two rooks using a cabinet with a double door—much like a magician’s prop. When the birds would place a piece of trash in a slot, Gaborit would pull a board to reveal a yummy snack below. Eventually, the birds came to associate tidying up with food and happily picked up cigarette butts and small pieces of paper.

Sometimes, though, the rooks got a bit crafty. According to Mindy Weisberger of Live Science, they would try to trick Gaborit by dropping pieces of wood, instead of garbage, into the box.

The trash-happy rooks will “work” four days a week under the close watch of a falconer, who will make sure that people don’t toss garbage onto the ground just to watch the birds pick it up. The purpose of the project isn’t really to get the park cleaner—it’s already quite tidy, Puy du Fou President Nicolas de Villiers tells the AFP. Instead, Boubou, Bamboo and Co. are there to show visitors that “nature itself can teach us to take care of the environment,” Villiers adds.

Follow the rooks’ suit, in other words, and pick up your trash. The lesson is intended for human visitors, but certain sloppy corvids—like these ravens that outsmart trash cans—could probably stand to learn from it as well.