Why do ducks and swans have the oiliest feathers?

Well, honey, ducks and swans have oily feathers because they secrete oil from a special gland near their tail called the uropygial gland. This oil helps waterproof their feathers, keeping them dry and allowing them to float on water without sinking like a stone. So, next time you see a duck looking all fabulous in the water, you can thank that oily gland for keeping them afloat and fabulous.