This is my second time hatching bought fertile eggs under one of my broody Pekin bantams. With the first, all six hatched no problem at all at 22 and 23 days. This time I've had nothing but issues! Half the eggs either didn't develop or failed by 15 days. The first pipped two days late in the evening. I went down next morning expecting a newly hatched chick and instead found a stone cold egg with the beak just poking through, not moving at all. I broke open the shell figuring what harm could I do now, and it moved! After warming it up, I had a live fluffy chick two hours later! I kept it in and warm until the second egg hatched later that day (without incident) and put the rescued chick back with its sibling under the mama. But there is still one egg unhatched four days later (and six days past the due date). I don't know exactly what day the eggs were laid but the cut off point had to be the day before I received them in the post. I can hear movement and tapping inside. I've put the egg under another broody as the first hen has left the nest with the two hatched chick so I guess she's lost interest in the egg to focus on her chicks. She's not been the most attentive mama. Could the fact I often found one or two eggs cold each day have slowed down the chicks' development and caused the delayed hatching? If I'm hearing movement, do I keep trying to hatch this last egg? Break it open? Give up? How long can they go until hatching?