Indian runner ducks have been used in Asia for thousands of years to control pests. Now they’re being used in a South African vineyard to eat snails that damage the vines. On the Vergenoegd Wine Estate, in Stellenbosch, South Africa, about 1,000 of the well-behaved quackers parade twice a day into a vineyard to rid it of pests, as they have done for at least 30 years.

Denzil Matthys, the duck caretaker at Vergenoegd, confirms that the ducks help make the farm sustainable. “We try to keep a pesticide-free farm by using the ducks,” he says.

Marlize Jacobs, the farm manager and winemaker, says snails are a big problem at Vergenoegd because of the vineyard’s proximity to the ocean. “After winter, the vineyards bud,” she says. “Those buds are succulent bits of food and snails love to eat them. If we don’t control them, they will absolutely destroy the vineyard.”

Watch a video at Tinyurl.com/DuckPestControl.