Hi I've been trying to hatch chicken eggs. I've done this several times now, and very successfully but now I don't know why but they aren't hatching. When I candle the eggs, I know they're ferliized and developing. I check the temperature and humidity twice daily to make sure it's just right. The babies start to make the peephole then they just die. That's happened to all the eggs the last two times I've tried incubating them. I have eggs in the incubator now and two just started making peepholes. I'm worried they might just die. Is there anything I can do to make sure they don't die? And why would they even be dying after the peephole? I don't lift the lid after day 18 except the tiniest bit to add water. I'm not sure was going on I've never had this happen before.