We had a pair of mallards build a nest in a bush right next to our driveway. Since I parked my car right there, I always had a good view of the nest, and was really careful. I ended up parking at the end of the driveway, since I was afraid I would startle the mom into flying away, and maybe right into my car.
Anyway.....DH called the ag office, and he was told that the mother will lay an egg or two, every day or few days until she has about 8-12, and then will sit on the whole pile of them. They all hatch the same day too.........remarkable. Takes about 3 weeks to hatch. We missed the actual hatching, though, and we were checking every day towards the end. ANd then there were just empty shells. As soon as they are hatched, she will parade them to the nearest water. Do you have a pond in the area? We do, and when we realized they were gone, we went to the pond, and they were out there swimming......I assume that it was them, since we don't usually see mallards around here.