All mollusks build their own shells, whether they live in water or on land. Creatures like snails, clams, oysters and mussels use an organ called a mantle to secrete layers of calcium carbonate ...

Common Eider bird or common duck standing shaking off fur on the coast of glacier lagoon in Jokulsarlon at Vatnajokull national park, Iceland Flock of common eider (St. Cuthbert's duck) birds swimming ...