I only have 2 now Philippa, from the original 4.
One got sterile peritonitis, had treatment from the vet but never picked up. The other died a few weeks ago. She had a bone infection when I first got her and couldn't walk, she used to try and drag herself around by her wings. I got her sorted out and she recovered and was able to walk in a waddley kind of way and then became chief hen. I thought she was on her way out and made the decision to just let her die at home with her pals seeing as how she'd spent so much time at the vets in her short life anyway
It's just one of those things. I'm sure they're worn out from the 'enriched cage' system so I'm not really fussed about the eggs.