I have a broody silkie momma who has been sitting on some eggs for quite a while. I noticed one day that there was an old looking egg close to the door of the coop. I figured one of the other girls laid it there. I picked it up and it felt rather light and half empty. I cracked it open and out came pure black gunk I'm guessing my broody hen moved it there away from her nest. Broody hens just amaze me!