Do ducks know which eggs aren't fertile?

[duckmanjim]

My mallard hen had a nest of 16 eggs! We are on week two of her incubation. In week one she pushed 6 eggs out of her nest! One or two a day! I placed them in an incubator and now after one week im seeing no veins in the eggs from candling. Do they know which are fertile and which arent?? She hasnt pushed any more out in the past week.

 

[Virus]

Yes, somehow they know which eggs aren't worth their time. I can't tell you how but they know when something's amiss.