I am fairly new to raising chickens. My FIL has hatched some years ago, but he doesn't know what I'm doing wrong. We have had three batches of eggs, all fertile, and all end up with fully formed chicks that don't hatch. The first two batches were in a home-made incubator, but this third batch is in a store-bought one that stays pretty consistent in temp and humidity. We have heard the eggs chirping, but then they never hatch. There is a decent amount of fluid in the egg when I have autopsied them, so the chicks don't seem to be getting stuck. The last incubator had tons of ventilation holes and stayed around 60% humidity. The one we bought is an LG. I have two thermometers, one of which also measures humidity. It is now at 50%. I have two eggs due in the next double days, and a couple more due later. The eggs are from different breeds of hens, and two different roosters (possibly three, there is a feral roo that gets into our pen). We did have one chick that I helped hatch out after he seemed to just get stuck, but he died when the temp in the brooder took a nosedive. What am I doing wrong? I'm not too sure how many more chick deaths I can really take.