Is this the same egg? To me looks like a quitter, the entire egg should be black, you shouldn't be able to see much at all exspecially if you are in Lockdown??
Candle it, if it's going to explode, which I doubt it very much, the entire egg will be BLACK even the AIr cell, you can smell the egg and if it's bad, it will give off a bad odor, usually bad eggs will give this odor off if you just lift up the lid. Then it's like a guess game of: OK WHOS THE BAD EGG.....I just put my duck eggs in lockdown 2 days ago. One egg has developed a blue/gray coloration on the shell where the air sac is. Have any of you experienced that before? Is the duckling dead? One other egg has a small blue dot on the side. They were completely white at lockdown day 1. The temp dropped to 97 for most of the first day while I was away. I was able to bring it back up to 99 but I wonder if this affected the eggs. The incubator maintained a steady 100 degrees right up until lockdown (of course I would have problems when I am not suppose to open the door!). The humidity is at 70-75%. Both eggs showed movement when candled before lockdown. Should I remove them from the incubator? I definitely don't want an explosion if they are bad. Advise is much appreciated! Here is a picture of the blue coloration (bottom left egg):
