Eiders are a species of duck renowned for their down feathers, which are used to make high-quality insulation and clothing. They are found in the northern hemisphere, particularly in coastal areas of the Arctic Ocean, North Atlantic, and North Pacific. Eiders are large sea ducks, with males having a wingspan of up to 1.5 meters. They have a distinctive black and white plumage, and their down is highly sought after for its warmth and lightness.