I have four hens, 1 year and 3 months old. All started laying last August and have laid pretty well, even a few through the winter. However, starting in April, one of them (I am 80% sure it is my Rhode Island Red) started laying some broken eggs. Then she didn't lay at all for a while. I gave more calcium (oyster shells, chopped up chicken shells and powdered calcium). In late June, we finally got some four-egg days. However, last week, the bad eggs have started again. Today I had to clean a real mess out of the laying box. Does anyone know a fix for this? Otherwise, I think I am going to have to learn how to kill a chicken. I don't want to keep feeding her, and I don't want her problems to rub off on the others. I have an Amercauna, a barred plymouth rock, and a black sex-link. Thanks for any help.