Why Can Ducks Swim?

On the tip of a duck's tail there is a grease gland which can secrete "oil." Duck always smears the oil on its feather-s with its bill, so the feathers don't get wet. Besides, duck floats on the water like a small boat because of its dense, thick and soft feathers. There is also a layer of skin between the toes of the duck, which looks like a small fan and is called a web. Duck paddles the water with its feet, just like a rower uses oars. So, ducks can swim on the water.