Sheep munch on invasive plants at Atlanta airport Courtesy of Hartsfield-Jackson Atlanta International Airport. A sheepherder checks a flock of sheep munching on vegetation at the Hartsfield-Jackson Atlanta International Airport. Goats do it in San Francisco. Now sheep are doing it in Atlanta. As part of a pilot project, 100 grazing sheep (plus a few goats) are hard at work this week eating invasive plants such as kudzu on property belonging to Hartsfield-Jackson Atlanta International Airport. The sheep are hired from Ewe-niversally Green and are part of the "Have Ewe Herd?" program hosted by Trees Atlanta, a nonprofit group dedicated to planting and conserving trees. Bethany Clark, a Trees Atlanta spokeswoman, told NBC News that the airport had heard about their programs and asked to borrow the sheep for a week. "The airport will evaluate the effectiveness of the sheep, and we'll go on from there," she said. Clark said that, while on duty, the sheep are protected by an electric fence and have both shepherd dogs to keep them corralled and guard dogs to protect them from predators such as coyotes. There's also a human shepherd who checks on the sheep a couple of times each day. Goats from Goats R Us have been munching weeds at San Francisco International Airport for at least eight summers. "They are hired help and used seasonally in an area that is home to two threatened species: the San Francisco garter snake and the red-legged frog," said Michael McCarron, SFO airport spokesman. The goats are easier to use than heavy equipment and we expect them to be back next year. In 2008, Seattle-Tacoma International Airport hired a herd of goats (and three sheep) from Goat Trimmers to spend 12 days eating wild blackberry bushes, Scotch broom and other weeds around the airport. They have not been invited back. "One of our struggles with the goats is you have to protect any foliage you want to save," said airport spokesman Perry Cooper. If you have an open field it works great. But when you have areas and plants you want to save within that area, you still have to use staff to build protection barriers. For us it wasn't the best solution.