Don’t throw those egg shells away. Recycle them back into your chickens. Yep, feed them to your hens. In one end, out the other…or I guess it would be out one end and into the other…uhm…well, yes.
Why?
Egg shells are a great source of calcium for chickens. If you’re raising layers, you’ve probably got them on a layer food (if you don’t, it would be a good idea to switch to one) and that layer food is specially formulated to give hens what they need during their laying years. But extra calcium still needs to be offered to the flock. This can be in the form of oyster shells (which you can buy already ground up at the feed store). Or you can use egg shells. I actually use both oyster shell and egg shells. But hands down (or would that be beaks?), my hens way, way, WAY prefer the egg shells (personally I would too…they’re prettier and smell better).
It’s easy to prepare egg shells for the chickens. Here’s how:
1. Save a bunch of egg shells 
2. After you have enough to spread out on a cookie sheet, stick them in a 225 degree oven for about 30 minutes. (This kills all the germs, etc. that might be lurking and also keeps girls from realizing they’re eating eggs–you don’t want to encourage that kind of behavior).
3. After the shells have baked, dump them in a bag and roll over them with a rolling pin a bunch. You want them crushed up pretty fine. 
4. Always give extra calcium to your flock as a free choice (put it in a container separate from the feed). They know when they need it and they will get it themselves. 
I’ve heard some say that feeding egg shells to chickens is a bad idea because it will start your hens pecking on their fresh laid eggs. I’ve been doing this for years, however, and I’ve never had an egg pecking out break because of it. I don’t think they realize that those baked bits of shell are the leftovers from an egg they laid before.
I often mix the egg shells in with oyster shells because the girls love the egg shells so much they see it as another food group and consume it in large quantities, which probably isn’t the best thing. Mixing it with oyster shells extends the ‘coop life’ of those shells significantly.
If you have egg shells coming out your ears, besides being a good source of calcium for your flock, here’s several more ideas of what you can do with them. Egg shells are amazing! I can’t imagine why people might think they are trash! My girls wouldn’t understand that either. They come running when they see a bag of freshly baked and crushed shells in my hand. Mmmm. Mmmm. Eat up!
