The rising

Muscovy duck raising its crest of head feathers

Muscovy ducks don't generally make much noise. While the mother ducks may get a little squeaky at times, Muscovies don't quack. They just make sort of a soft hissing sound. But if you observe them long enough, you will find they have even quieter, yet noticeable, ways of communicating. When they're excited or feel challenged, they may raise the hair on their heads. Sometimes it goes up and own, and then up and down and ... up again ... as in the photo above.