I just candled my 9 eggs I'm incubating and WOOO HOOOO there is definite development, vains stretching from here and there with a small red well defined embryo shape in the center!! Just like in this link on day 6 but cleared and more defined. http://www.metzerfarms.com/Candling.cfm?CustID=147653 It was as clear as the nose on my face!! However, the other 8 look just like they did on day 4 when I candled just yellow yolk, no defined vains or centered embryo shaped in the center and light all the way around, I could see . OMG I am so super excited!! I will candle the other 8 in 4 more days, and if they are all the same as now, toss them and continue with #10 incubating. I thought I saw something on day 4 with #10 and now here just 2 days later how GORGEOUS #10 is looking and coming along! I'm doing it! I'm really doing it, I'm momma duck!! Like I said, if I can have 1 or 2 survive I will be so happy! Momma is still laying ,she is up to 8 in the igloo, so far she has laid 19 total, but 2 broke. Gosh I would love to buy another incubator and try to incubate the ones in the igloo, but we'll see what she does on her own. How long will eggs stay good once she quits laying but doesn't brood?