how many eggs can a duck sit on ?

[mycountrycabin]

how many eggs can a duck sit on? the duck is a mallard and its my grandmasand they never hatch and taday i noticed she was sittin on 21 eggs is that too many?

 

[ohiofarmgirl]

our smallest momma 'scovy hatched 18 out of 20 eggs!!! then two babies from our other momma 'scovy left her and came to be with the big horde!

 

[1lpoock]

21 might be a bit too many for a mallard. I've seen a mallard sit on up to 10 or 11....some of them just won't hatch.