Well, the incubator was really inconsistent (eggs got up to 106 F), so only 45% of the eggs hatched. To see what happens, I dissect the eggs to see how far developed the embryos get.
Imagine my surprise when I opened up one of the eggs, and found two ducklings attached to one yolk! Most people have heard of double yolked eggs, and less then 0.02% of eggs have this. Of these eggs, 1 out of 200 can hatch.
These guys were very advanced in development, as they usually die in the first week. They compete for space, oxygen, and resources.
Interesting! It would have been neat to see them hatch if they would have lived.