All true ducks, except shelducks and sea ducks, become sexually mature within the first year. They pair only during the breeding season, unlike swans and geese, which pair for life. According to the unique behaviors of ducks, ducks can be divided into three main groups: tealing ducks, diving ducks and perching ducks. The mallard is a typical teal duck and the ancestor of most domestic ducks. Roosting ducks such as the Moscow duck have long claws and are the most arboreal ducks. There are the most species of diving ducks (including marine ducks). Mallards fly from the south to the north to lay eggs in spring, and then fly to the south to overwinter in autumn. After they were domesticated by humans, they lost their ability to fly. In order to obtain more duck eggs, people did not let them stop producing eggs and hatch them. Over time, domestic ducks lose the ability to hatch eggs. A ducks eyes have a 360-degree field of vision, allowing them to see behind them without turning their heads.
