My hens were running to the hen house when one of my buff hens dropped an egg. It was a party for the rest of the hens. Once the egg was eaten, they all proceeded to the hen house. What is up with that?
Sad to say but often egg eating when started can't be stopped. If you want eggs you will have to either start over with new layers or work very hard and diligently to try to break the habit. It has been my experience that once started many hens are never broken from egg eating. They know a good thing and don't forget it.
Your hens need high sources of protein. You can boil them some eggs and feed them back chopped (with shells) mixed with some cooked white rice and yogurt. You can toss out some black oil sunflower seeds and dry kitty kibble. Careful on the kibble though it is made for cats not chickens and you don't want to get their minerals off balance. You might even buy some crickets and meal worms.
You will have to check for eggs often and frequently in the day. You may even have to lock them up until lay and then collect eggs and let them out 1 at a time.
If I were you I would go ahead and get some chicks and start growing them out to replace the current layers.
Once when I only had three in a very small tractor, they ran out of water. That was the only time I have ever had an egg eaten, and I am sure it was for the moisture. It never happened again. However, I have heard that in normal circumstances, once they start, they need to become chicken & dumplings.
Any time an egg gets accidentally broken near my chickens they will eat it but they never have tried to eat them otherwise. I think it only natural for them to "scramble" for the egg (pun intended!)....they treat everything else that hits the ground the same way!!! Little hogs!
Now, my grandmother would occasionally get a hen who ate eggs intentionally and she made soup each time, but I have never had that problem yet.