The term 'Black and White Duck' refers to two species of ducks, the EIDER (5 letters) and the SMEW (4 letters). The EIDER is a large sea duck that is found in coastal areas of the Northern Hemisphere. It has a black and white plumage and is known for its soft feathers which are used to make down products. The SMEW is a small freshwater duck that is found in Eurasia. It has a distinctive black and white plumage with a white head and neck, and a black back and wings. Both species are popular among birdwatchers and hunters.