Eiders are large sea ducks that are commonly found in the northern hemisphere. They are renowned for their beautiful feathers, which are used to create valuable down-filled bedding and clothing. There are several alternative names for these ducks, including the common eider, sea duck, and king eider. Additionally, they can also be referred to as coots or scoters, although these names are more commonly used for other species of sea ducks. Despite their popularity among hunters and collectors, eiders are also important parts of the ecosystem, serving as indicators of environmental health and helping to support local food chains.