In a remote corner of Chicago’s O’Hare International Airport, far from its high-profile modernisation mega project, a decidedly more low-tech initiative has been launched this week involving a herd of goats, sheep and llamas. The mission of the roughly two dozen animals: to mow the grass. And lots of it.

O’Hare is one of the largest airports in the world and takes its environmental initiatives to serious and sometimes quirky heights.

It has acres of green roofs and has even turned over a wooded patch of land to one million bees living in 28 beehives. The  honey they produce is sold in the terminals and the project helps replenish declining bee populations.