Duckling Sexing Help

[honestlyghost]

Hello! So I got my ducklings just the day before yesterday, and they're a straight run. I've researched carefully how to vent sex and have checked all of them - I have four Cayugas, one Blue Swedish, and one Black Swedish. I know that the Blue Swedish is a girl, but for the darker ducklings it's harder to tell - for when I invert the vent, there's a little black spot on all five of them, but it doesn't stick up or anything? So is this the penis or is it just a darker coloration?

 

[Aunt Angus]

Most folks don't attempt vent sexing, so I have no idea. I would think YouTube might help answer your question.

Good luck!