[Joe 6-pack]

"According to researchers, while male ducks have developed longer, spiraled genitalia, the females' anatomy has evolved to spiral in the opposite direction."

Sounds like a recipe for crossed-threads.

[refermech]

Actually a fella couldn’t even get the screw started! Bummer dude!

[r9etb]

Sounds like a recipe for crossed-threads.

Which says that the successful male duck gets stuck, thereby blocking access for unsuccessful male ducks...