Duck? What about duck? Duck: Duck is the common name for a number of species in the Anatidae family of birds. The ducks are divided between several subfamilies listed in full in the Anatidae article. Ducks are mostly aquatic birds, mostly smaller than their relatives the swans and geese, and may be found in both fresh water and sea water. Most ducks have a wide flat beak adapted for dredging. They exploit a variety of food sources such as grasses, aquatic plants, fish, insects, small...