I don't know what it is? I have had 2 of my worst hatch rates back to back. All the chicks grow in the egg but die before they come out. Some pip and then die with their beaks out of the egg. I just opened up about 9 eggs and all were dead except 1. I had 5 hatch out of like 15. I keep the temp at 99-100 and humidity at 50% and on lockdown I bring it to 70-75%. I clean the bator with bleach after every hatch. I use the hovabator.The only thing I can think of is that my digital temp sensor is off. WHAT AM I DOING WRONG AND WHY ARE THESE CHICKS DYING?