Why are Call ducks hard to hatch?

[WallacetheKhakiCampbell]

I think the title asks the question well enough , so what is it about call ducks that makes them hard to hatch? I am really wanting to hatch out a few eggs this season for the first time. Im really hoping for them to imprint which is part of the reason I want to hatch them myself. Also, does anyone have experience/opinions as to whether cooling the eggs daily and misting with water helps?

(any leads as to where I might find some eggs would be great too )
I've found eggs from Open Gate Poultry selling a half dozen for 40$, that seems to be the only verifiable place I could find for eggs.

Thank you!

 

[Sleepytime]

If they're from show quality breeders, their short bills sometimes have problems cracking the egg shell.

 

[JacinLarkwell]

Their shortness of their bills can male male hard for them to pip and zip

 

[WallacetheKhakiCampbell]

If they're from show quality breeders, their short bills sometimes have problems cracking the egg shell.

Their shortness of their bills can male male hard for them to pip and zip

Ahh that makes sense I didn't think about that.