We often describe the embarrassing situation of being completely soaked as "a drowned chicken", just like a chicken that falls into water or gets rained on, with its wet feathers sticking to its body. But surprisingly, ducks never worry about getting wet in the rain. They still walk leisurely, and even after being drenched in heavy rain, they don't get wet. Moreover, ducks can swim in the water and even dive. After getting out of the water, they just shake their bodies and their feathers will still be dry. Why is that?
In fact, whether it's a chicken or a duck, their feathers themselves are not waterproof. The clever thing about ducks is that they have a tail gland at the end of their tail, which can secrete oil. Ducks often turn around to groom their feathers, which is actually a two-step process: first, they use their large, flat beaks to pick up the oil at the tail, and then they apply the oil to their feathers. After this treatment, the feathers become waterproof. However, chickens don't have this gland, so their feathers can't be waterproof. Once they get into the water or get rained on, they'll inevitably become "drowned chickens".