CHICAGO About two dozen goats, sheep, llamas and burros are working at Chicago's O'Hare International Airport.
The animals spent Tuesday afternoon munching their way through about 2 acres of brush on the northeastern corner of the airport. Aviation officials say they goal is to eliminate tall grasses that serve as habitat for birds and other wildlife.
Those animals can cause problems for pilots, like getting caught in engines or cracking cockpit windshields.
O'Hare International is one of the largest airports in the world and it takes its environmental initiatives to serious and sometimes quirky heights. It has acres of green roofs, including one atop an air traffic control facility, to reduce storm water runoff and lower the urban heat island effect of the airport's massive concrete expanse.