I have 18 cold comets that are great layers,but one of the hens lays an egg with the shell so thin I can't pick it up without it breaking.the last month she has started eating the egg,I have tried oyster shell,cut out the treats,everything I could think of but nothing works,I don,t understand whats going on with this bird.all the others lay beutiful brown eggs with very hard shells and they all have the same diet.the egg even looks different,about 1/3 of the shell is light brown.then a dark brown circle around the middle of the egg like a band,then the other 1/3 is light brown,she has had oyster shell for months but its time to cull,this bird has been laying eggs like this since she started laying and she is over a year old,has anyone else had this problem and if so,what did you do to try to correct it?any information would be greatly appreciated,I am beginning to think it may be genetics?