Yeah, ducks of either gender are randy critters. If it doesn't bother you don't pay them any mind as long as you continue to get 4 eggs a day.
Oddly I have a pair of magpie/black swedish (God only knows) mix hens who didn't lay at all last year and their voices started to get more of a "teenage boy voice crack" quack and they were mounting each other and my other females... Then I got a lot of boys from a neighbor to be processed, and of the 9 drakes I still have two left who make a job of makin ducklings with every girl they can. Since then my weird "butch" ducks have toned down their behavior, get male attention regularly and are back to laying regular.
It's weird but I've seen lots of stories about female ducks who swap genders in life, hormones do strange things to birds.
