Then I put the ground egg shells out for my chickens to eat, they love them. It puts the calcium and grit that they need right back into their bodies to make their next eggs.
The trick is to make sure that they don't look like egg shells to them, so that they don't eat their own eggs or another hen's eggs. Birds love eggs as well as egg shells and when they start eating eggs it is hard to make them stop.
When babysitting our neighbor's parrot, I feed her boiled eggs and she loved them. I haven't done it but I'll bet my chickens would love boiled eggs as well.
Chickens love protein and will eat meat, worms and insects are their favorite food of choice, they prefer these delicacies over corn and seeds.
I noticed the other day, one of my Barred Rock hens running for her life past the bedroom window. So I went to see what was chasing her, it was the other hens and the rooster. The funniest thing you ever saw was this hen running all over the place with a dead mouse in her beak with all of the other chickens in hot pursuit. One of them finally grabbed it and a tug-of-war began until the other hen won the battle and ran for the hills. She found a good hiding place and enjoyed her trophy. I tried to get some pictures of the chase but they were too fast for me.