They are great entertainment value. I have an "odd" duck named Buckette. She never stays with the flock, bobs her head oddly most of the day, and spends most of her time with one eye to the sky. Not sure what she's looking for. We actually think she acts autistic with her rocking motions and loud vocalizations.
i have a crested girl who has a side ponytail. she has this skin flap with feathers on the side of her head. she also cocks her head to the side as if she's posing for a yearbook picture. Something about cresteds possibly having brain damage????