Good News of the Day: Army of 1,000 Ducks Used as Brilliant Pesticide Alternative Resource Type: Article Published: 2016 South Africa's Vergenoegd vineyard in Stellenbosch keeps a flock of over 800 Indian Runner ducks to help combat tiny white dune snails that would otherwise destroy the budding vines. The ducks' upright and slender posture allow them to navigate the rows of plants, clearing up to a hectare a day.