5 newer ducklings (not from here) soon began to get a some sort of greasy substance around their heads. Their heads are greasy and brown hard chunks are hanging from the feathers. We haven't seen them have mucus from the nose or ears, and have not seen them have infected eyes. They do sneeze now and then, but not a lot. Water seems to make it itch more. We went to the bird vet, she tested on mite, lice, and other critters. It was none of those. She didn't know and send pictures of the ducks to the university of birdscience. We are still waiting for an answer. With so many birdproffesionals here, maybe someone has an idea?