I think Rosetta channels an ancient Irish washerwoman. Nothing makes her happier than peeling the paper layer off of her cardboard cage-carpet and then taking it to plunge it into her pink cat-box, swooshing it around in the water until it's sodden, then swinging it around in circles with her beak as if to sprinkle the immediate area. I don't know why she does this, but oftentimes we have to change out her water because it's so full of papier mâché there's no longer room for her!
Oddly, Madge has recently begun 'washing' her cage carpet as well. Maybe it's a nesting thing? Or something?