When I hatch ducks myself, the last few to hatch always seem so much smaller than the others for several days, because they grow so fast that even a 36 hour difference in age makes a difference. But this time is a little different, and I'm wondering if anyone has any insight. All seven ducks are vigorous and active, eating and drinking. Two of them are about 2/3 the size of the others and skinny... and scraggly. It's like their down never quite fluffs out properly. One of the two had a hard time hatching and dragged his umbilicus for a while and had to have a couple baths to get the stickiness off of him. One of his wings was glued to his body with gunk until I washed it for some time in warm water. The other one had a normal hatch. All the ducklings hatched late last week. Neither of these ducklings are birds I was planning to keep, but I don't feel good about selling a bird that's not thriving either. Anyone have insight into what might be causing this and the likely prognosis? Like I said, they are active and behave normally. Thanks!