Duck feathers are so waterproof that even when the duck dives underwater, their downy under layer of feathers will stay completely dry.
A duck’s bill is specialized to help them forage in mud and to strain food from the water. A hard nail at the tip helps with foraging, and comb-like structures on the sides strain small insects and crustaceans from water.
When constructing her nest, a hen will line it with soft down feathers she plucks from her own breast.