Waterfowl (ducks, geese, and swans) get their name from their tendency to stay in or near water. Their feathers are densely packed and waterproof, streamlining and insulating them for aquatic life. Nearly all waterfowl feed in the water, on aquatic grasses, seeds, roots, insects, mollusks, crustaceans, and/or small fish. Their webbed front toes help them paddle around looking for food. Typically, waterfowl have long necks and flattened bills with spiny tongues to grasp slippery food. Different species of waterfowl have different feeding techniques related to their diets. Mollusk-eaters use strong bills to yank mollusks off rocks, while fish-eaters have long, pointy bills for catching fish. In dabbling ducks, water is sucked in at the front of the bill, then pushed out the sides by a fleshy tongue. Hard, filter plates (lamellae) along the sides of the bill trap food like a sieve. Waterfowl often feed in flocks, making chattering sounds.