I have a hen who sat on a batch of eggs for more than three weeks. Becoming a little concerned, my wife decided to check for chicks and when she lifted the hen she found a broken, rotten egg. She sprang into action and immediately came to get me to clean it out. I removed the remaining eggs to clean the nest but when I placed them aside one of them exploded! Thinking they might all explode, I got rid of all. My question - Is this a common thing...is there a general explanation as to why eggs go bad when under a chicken? I presume all of them were bad (7). I don't want to go wrong again when trying to hatch some eggs. I am new to all of this.