The Chicago O’Hare International Airport has turned to grassroots efforts in clearing its overgrown vegetation. Since 2013, the airport has hired a herd of sheep, goats, llamas, and burros to clear plants that are difficult to maintain with traditional equipment. Observe the more than 40 four-legged lawnmowers happily munching away on greens—even chomping down on poison ivy and noxious weeds. The animals come from a nearby rescue facility for their seasonal duties and their efforts mean no pesticides are needed to maintain the 120 acres of land surrounding Chicago O’Hare. And airport passengers fear not—runways are separated from the grassy fields with security fencing so the animals keep a safe distance from taxiing planes.

For more information, visit the Chicago O’Hare International Airport.