In small numbers, ducks are harmless and fun to watch. Unfortunately, large numbers of ducks and geese will contaminate lakes, ponds and their surrounding areas with unattractive and unsanitary droppings. If ducks are becoming a problem in your area, there are several natural ways to repel them without harming them or disturbing the peace.
Cut long strips or flags out of bright fabrics. Tie them to tree branches wherever ducks are a problem, or set up a clothesline and hang your fabric from it. Make sure that your fabric blows freely in the wind -- that movement, combined with the bright colours of your fabric, will scare away ducks and geese.
Let grass, especially grass along shorelines, grow to at least 10 to 14 inches. This will interfere with ducks' line of sight and will discourage them from using the area.
Build up an 18- to 24-inch vertical bank at the edge of your ponds and lakes, using a shovel. Ducks will avoid swimming in bodies of water if they can't easily climb in and out.
Walk your dogs or let your dogs run around areas where ducks are a problem. Free-running, barking dogs are especially frightening to ducks.