Also, female ducks have corkscrew shaped vaginas they can contract or relax. This is to protect against rape and to only mate with desirable males. It's basically an arms race b/w duck dicks and vaginas. Ducks trying to be as as close to the vagina structure as possible, while the vagina tries to be as hard to get in (without consent) as possible.
Also, female ducks have corkscrew shaped vaginas they can contract or relax. This is to protect against rape and to only mate with desirable males. It's basically an arms race b/w duck dicks and vaginas. Ducks trying to be as as close to the vagina structure as possible, while the vagina tries to be as hard to get in (without consent) as possible.