A fox came and killed my call flock. 7 adults. 2 hens were brooding 27 eggs between the 2 of them. All the eggs but 12 were destroyed also. 8 are still growing in the incubator. I marked the air cells at todays candle. My problem is, I did not mark the date the broodies started to sit on their eggs. I was letting them do their job and didn't candle or check their eggs untill after the attack. I honestly do not know how old these eggs are and when they are due. Can anyone guess about how far along they are by the size of the air cell? The babies are taking up 50% of the shell. One egg has a huge air sac, the others are about the same size. I do know one nest was about a week older than the other. I was so upset by what I found that morning, I didn't even mark what egg came from what nest. I am guessing they are around day 18-20, but I really don't know. I know nobody can tell me an exact age, maybe just a good guess? Thank you in advance! The 8 eggs left This one has the huge air cell One egg is a lot smaller than the others, but duckling is moving and growing like the rest. I have not incubated duck eggs before, I am wingin it at the moment. Temp is 99.5, humidity at 53%, forced air incubator, turning 3 times a day now (was 2). I was not cooling them, but am now for 15 min. I am not misting yet. Should I start, are the air cells too small? *UPDATE* It is now 6 days later and the air cells have grown in all the eggs but 2. Those 2 eggs are about a week younger. I added a new picture. Am I still on track? Should I put these in lockdown now and stop turning? Will the higher humidity effect the 2 eggs that are a little behind? I do have 2 broodies I could give those 2 eggs to. pic taken today 6/13 Thank you for everyones help so far.