The other night, I took in 10 wild duck eggs that are due to hatch in about 4 or 5 days (duck nest in our front yard--we've been monitoring daily). The mother was gone for over 24 hours and I stayed up until 4 am one night to be certain. I then took in 6 eggs and left 4 in case she returned, but no luck. So in the morning I took in the remaining 4. Candling shows life in 9 of the 10 eggs. In the 10th one I could see an embryo but it looks smaller that the others...but the egg is still a vibrant orange and I can see red blood vessels. Also, the egg doesn't smell bad. I've been doing hours of research on all of this! It went down to around 50 Fahrenheit when the eggs were still outside, so I was pretty excited when I saw life! I have them in a plant seedling tray with a seedling warmer underneath (buffered by towels). I'm also monitoring temperature and humidity according to research I've done. I plan to keep out of their sight, and hand them over to a wildlife center as soon as (if) they hatch. Any advice is welcome, as I am absolutely new to this! My main question is, what do I do about the one that looks like it's not developed enough? (it's about a third to half as big as the rest and there is no movement).