Second, this is a good question. Some hens eat their eggs and it if virtually impossible to stop them once they start. You might want to try and add more calcium in their diet by giving oyster shell free choice, to see if this will strengthen their shells and solve this problem for you. Other than that suggestion, I don't know what to tell you. Sorry.
Egg eating is a wicked bad habit. AS mentioned, once it starts it can be impossible to stop.
Egg eating is not due to calcium deficiency, but weak egg shells are easier to break into. So add calcium to ensure they are strong.
It is also not a protein deficiency, so don't worry about feeding them cat food or other extra protein sources.
Golf balls sound good, but unless you are collecting the eggs fast, they'll just peck at both until they hit the good ones.
Egg hollowed out with chili pepper stuffed inside are useless, too - chickens aren't affected by capsaicin, the hot element in peppers.
Egg eating is normally the result of an accident; some clumsy hen stumbles over the egg and cracks it, she spies the crack and starts pecking at it.
Or, she sees a spot of poo clinging to the shell and goes to pecking at that. Once one hen starts, the others follow.
So keep a clean nest. If you are getting eggs with feces on them, clean the nest and keep it that way.
Then, get out there and collect the eggs - ASAP. Dont leave them around for the hens to mess with.
Try hanging a curtain over the nest front so it is dark. Chickens wont peck at or eat what they cannot see.
Keep lots of soft litter in the nest for cushion.
Rollaway nests are an option, so the egg rolls out of reach where the hen cant get at them after laying.
In extreme cases, culling the offending hens is the final answer. It's easy to tell which one is guilty, too.... it'll be the one with egg on it's face (which is one theory as to where the term comes from).
Not too long ago I asked the same question because I was gettting the same little holes in the end of my eggs, all of sudden. Someone suggested making sure there was enough bedding in the layer boxes because the end of the egg can crack from the fall of a standing hen when they lay. I thought it was a long shot, but I had run out of bedding and the layer of shavings was thin. I filled them up nice and cushy and the holes stopped appearing for what ever reason ( happy hens or soft fall). Just a thought Good luck.
Today I observed two hens fighting over an egg: I think they were just trying to roll it under their own fluff, but it was a serious "peck peck peck" as they tried to move it.
I also have some retarded (
really) EE's who pile up two and even three deep for some reason...so I think they kick the dang egg into the wooden side of the box when they do that.
Why do I think they're retarded? Because I have a 5 foot communal nest and a two foot 'private' nest: for 13 birds! With a six inch wide landing platform/front patio for them to walk back and forth on and choose their spot from.
There should be no sitting on each other's heads and shoulders with that much dang room!!!
Are you sure they are "pecking" a hole? They could be stepping on the eggs (they have very tough and sharp pointed toenails!) Took me a while to figure out what mine were doing. I have one hen who insists on laying on the wooden shelf UNDER the nest boxes and almost every egg she lays, either she or someone else steps on and pokes a hole in it. I wouldn't have figured this until I saw them do it. I was figuring I had a egg pecker also.