Presumably they’ve all hatched now, but for future reference: opening the incubator must happen as little as possible if there are any eggs left that have already pipped. It’s ok if they haven’t pupped yet,
Each time you open the lid even for just five seconds, there’s this little draft of fresh air and the membrane around the chicks dries out a little bit each time, the humidity getting high again after you’ve closed the incubator does not make the membrane moist again. It makes a difference and can become problematic for the later chicks if it’s a bigger batch.
I ended up buying a bigger incubator to give the chicks more space after hatching (that was my excuse, anyway
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