I have some eggs that were in transit for at least 4 days, and a few had dates on them from one or two days before shipping actually began. Now, on day 12, a few eggs were soooo dark when candled, I was positive they were bad- I mean 7 others look totally different, the 7 have more obviously small embryo's, more free space in the shell, way more obvious movement. The 2 suspect eggs didnt smell, or sweat, but they are really far different when candled, very dark suddenly, very full, very little extra space, NO obvious movement. There was movement in them a few days ago, but then they got dark inside and I couldnt see anything. I have a really good light that is very bright and I never had problems seeing thru eggs with it. So, today I decided I wasnt going to let one explode in my bator, so I took the one I was 99% positive was rotten and broke it open. BAD mistake Inside was a big, fully formed chick with a full covering of feathers. And I think it may have still been alive There was still alot of yolk and no bad smell or discolorization of the contents. Needless to say I put the other suspect egg right back in the bator. I could just KICK myself. I feel awful. I am already soooo attached to these eggs/chicks, its ridiculous- I've even put off a family vacation just to stay home to hatch and care for the chicks. My question is- Can eggs begin developing during shipment? It seems like the 1 I broke open was more than 12 days along, and the other 7 eggs look very different when candled. Is it possible? How do I know when to put each egg into lockdown if they are developing at different rates??? Or am I wrong about development at the 12 day mark? Opinions? Personal experiences? Thanks!