My 6 baby chicks are a week old tomorrow hatched by 2 sitting hens. After about day 14, I had gone out to coop and found a missing egg and a bits of shells in her clutch. I suspected she had eaten it, perhaps to dispose of a bad egg. As time went on, I ended up finding a dead chick in her clutch and it did not look developed. I don't think it hatched at all but rather that she had pecked at the egg until she got it out. I think she knew it wasn't any alive and was disposing of it. Then, after 3 chicks hatched ( because the other 3 belonged to my other sitting hen), within a few days you could tell she was ready to leave nest to teach the little ones. She still have 5 eggs left unhatched, and she pecked at 2 of them, leaving the membrane intact, but I could tell that the chick inside was not alive. She ended up abandoning the nest all together to tend to her 3 little ones. I am only a year into chickens, and this was my first time with broody hens, so my experience is minimal. But based on that and consulting my friend/co-worker/mentor and learning from her, I believe mama hen knew which eggs were bad and taking care of it.
