I lost all of my last hatch due to a faulty thermometer. I was devastated. One of the eggs was very special to me. My favorite hen passed away unexpectedly and I had just happened to put one of her eggs in my incubator. The entire time my incubator was 8 degrees too cold. All the eggs had started to develop and then stopped. It was so tragic. Now I have a digital and regular thermometer in the incubator.