Shirley's gone crazy

[231stevie]

1 of my hens, Shirley, has just all of a sudden started eating the eggs. It's 3:41am and heard some noise from the chickens. I'm outside and Shirley is eating the eggs again. I bought oyster shell because I thought maybe she has a calcium deficiency. NOPE. WHAT THE HECK IS HER PROBLEM

 

[rosemarythyme]

What are you feeding them? Do they normally have a source of calcium available? How long has this been going on? Do you gather eggs daily, or why are there eggs available for her to eat at 3 AM?