Many birds, including guineafowls, take regular dust baths to actively maintain their plumage. It is extremely important for birds to constantly groom their feathers in order to keep them clean and functional. Most birds have a preen gland which secretes an oil used for grooming. Dust bathing helps absorb any excess oil, and helps to keep the feathers from becoming greasy or matted. The oil-soaked dust is then shed easily to keep the plumage clean and flexible. Dry skin and other debris can also be removed with excess dust, and regular dusting may help smother or minimize lice, feather mites, and other parasites.