Bowerbirds love discarded plastic. The males use colorful pieces to woo mates in an elaborate courtyard outside their nests. New research shows that another animal is putting our plastic waste to good use: two species of city-living bee have started building bits of plastic into their nests.

The bees that J. Scott MacIvor, an ecologist at York University, studies aren't social and don't build hives. They construct small nests in plant stems, tree holes and fence posts. To examine their nest-building habits in detail, MacIvor enlisted Toronto citizen scientists in the spring of 2012 to help place artificial nest boxes throughout the city.

When he checked them that fall, he found something unexpected: Megachile rotundata—one of the most commonly managed bees in the world—had incorporated pieces of plastic shopping bags into its nests in addition to the usual leaves. And Megachile campanulae, which typically seals the cells of its nest with plant and tree resins, had used plastic-based sealants, including caulk.

The findings, published in the journal Ecosphere, constitute the first scientific documentation of insects building nests with plastic. Bees routinely live inside plastic objects, such as straws, “but to actively gather plastic is novel,” says John Ascher, a researcher at the American Museum of Natural History in New York City.

The study offers another example of how animals adapt to human-dominated environments. “There will always be those that have adaptive traits or enough flexibility in their behavior to persist in a disturbed landscape,” MacIvor says. At least we hope so.