I have two brooding. They share a very big box, one on each side. One has claimed 8 eggs and the other 15. I’ve candles them about every 5 days to make sure the first hatch is going well. Every one of them was fertile and full of veins. I’m so shocked to find this this morning, this far into it. I was really hoping to start seeing some chicks in the next few days. It’s kinda discouraging honestly. I wonder how they would know it’s a bad egg..... interesting.