@deedee28
I believe Scovy Mama had a Muscovy girl who used to dance to music with head-bobbing.
They do bob heads to indicate attraction, but I suspect some of them just enjoy music.
At about this age, they start trying things out. Ducks don't seem to stand on formalities, they'll take turns on top, at least for a while at first.
Hormones are kicking in. May be time to set out the free choice oyster shell.