What happens to a bird feather after it touches oil-covered water? Oil spills coat everything on the water surface. Cleaning up that oil is harder than it looks. You run three experiments. First, you add colored cooking oil to a bottle of blue water. You watch where the oil goes and drop in a cork to see how it gets coated. Second, you build a mini shoreline in a pan. You try cleaning the oil with cotton balls and straw. You also test sponges and other materials. Third, you dip a bird feather in oily water and try to clean it. After cleaning, the feather no longer fluffs up or floats well. Oil strips away the feather's ability to insulate and repel water.