Smashing there own eggs

I hope some one can help me, I have 3 rescue battery hens (did have 5 but Mr fox got 2) they are still laying between 2/3 eggs a day but they have taken to smashing and eating them. I have tried the chilli egg, horseradish egg but they keep eating them!! any help would be much appreciated.

thanks

make sure they have enough calcium in their diet, mainly through their pellets/mash. Oyster shell supplement adlib is also a good source particulary for exbatts, are their shells a bit soft??? Collect eggs as early as you can,to remove temptation, another thing you can get is roll away nestboxes, or pop a "false" floor which is tilted to the back so the eggs roll back, lots of chopped soft straw may help too.