I have lost 4 hens since last October. They range from 9 months to 3 years of age. I suspect they may have become egg bound but I am not sure. They have all had a pasty butt, lethargic, weight loss & an enlarged abdomen. I cut one of the dead hens open & found what looked like a grapefruit sized hardboiled egg with a super thin, paper like shell. I now have a three year old silver laced Wyandotte showing the same symptoms. Any suggestions will be greatly appreciated. I had to fumigate the coop last fall because the bug problem in this coop was horrendous. I wonder if this could have started the problem because the hens started dying about a month after I did this. I used an Adams plus Flea & Tick Indoor Fogger & made the chickens stay out of the coop all day. I cleaned out the coop & put fresh bedding inside before letting the chickens back inside just before dark. This is what was recommended by a chicken expert at one of our local feed stores.