Sadly it is likely that you have an egg-eater(s). Watch them and find out who is doing it (the culprits will have yolk and bits of shell on their beaks and/or face). When you figure out who, remove it/them from the rest of the flock immediately so the behavior doesnt rub off.
For the culprits; crack and beat up an egg, pour black pepper (plenty) in it and give it to it/them to eat inside the cracked shell. They will hate the taste and it should break the habit. Do this a few times to make sure it takes. When you feel it has worked, before returning them to the flock, put a few good eggs in with them to make sure the habit is broken. If they dont crack and eat them, success!
Meanwhile, make sure you are giving them PLENTY of oyster shell or limestone, as that is crucial for harder eggs. They may have started pecking them because they were a little soft, and naturally theyre gonna eat whats inside.
For a quick vit D/calcium boost, you can feed them whole milk while youre breaking them, as they also could be deficient which can cause them to eat eggs. Also make sure theyre getting a good laying pellet or mash from here on out.
Good luck!
