The road where Tammy's mother lives has a small creek running more or less parallel to it. This creates a series of back yards that are bordered by this creek. The creek was very nice and relaxing to listen to. And the Mallards liked it too. In fact, the Mallards loved the creek, and all of the nice lawns right next to the creek. I only counted about six adults while they wandered from yard to yard, across the road, back into the creek or wherever, so it was not a gigantic population of ducks. They were, however, attempting to change that.
Apparently it is not uncommon in the neighborhood to find a nest with eggs, but most get destroyed because they are in people's yards. At least one, however, was successful. The picture below was a photo I took facing upstream, looking between the railing and floorboards of a little bridge, at a single female Mallard and thirteen chicks! That is a whole lot of Mallard potential there, and another shining example of the Mallard master plan for controlling the world.