Although wild ducks such as mallards (Anas platyrhynchos) are attractive and sometimes entertaining birds, they may become a nuisance when they start to congregate in large numbers. This is most likely to happen if you live near a river or lake or have a garden pool or swimming pool on your property. If the waterfowl begin to dominate your water features or damage your garden, while polluting your property with their feces, you may need to take steps to discourage them.
Refrain from feeding wild ducks, either deliberately or unintentionally. They are attracted to seed that falls from bird feeders, so keep it cleaned up or install catchers beneath your feeders.
Break up the large expanses of short grass that ducks prefer by planting lots of trees and shrubs. If the water birds invade from a nearby lake or river, allow brush or tall grass to grow on its banks where it adjourns your property. When the ducks can't see where they are going, chances are they will find an easier place to climb out of the water.
Remove heating devices and aerators from your pond or garden pool, and allow the surface to freeze during the winter, eliminating the open water that attracts ducks during that season. Cover your swimming pool during the seasons it isn't in use, too. If you must leave it open during the summer months, float beach balls or rafts on its surface, as their movement may frighten ducks away.
Install flags, balloons and/or scarecrows on your property. Acquire balloons under 2 feet in diameter, with painted eyes in their centers. Attach them to stationery objects with fishing line, so that they float at a height of about 10 feet. You can make flags by tying 6-by-30-inch pieces of orange plastic or Mylar to the top of 4-foot stakes. Scarecrows should be as brightly dressed as possible, with large eyes and limbs that move when the wind blows.
Set up motion-sensing lights or sprinklers where wild ducks are most likely to congregate. Although they like water, they don't enjoy being abruptly showered with either it or light.
Display plastic, life-size models of animals that frighten ducks, such as dogs, foxes and raccoons. Those should be moved frequently or the birds will become accustomed to them. The presence of a live dog on your property should discourage ducks from visiting as well.