We have 6 chickens and we've noticed that 4 of them have lost all the feathers around their bum area. It's odd because the chickens who have lost feathers in these areas have lost them all in exactly the same places and they are all the same size of lost feathers. But not ALL our chickens have lost their feathers! We know it's not an alpha thing because the top 3 alpha-most hens have lost their feathers as well as the bottom ones. The only ones left untouched (for the time being) seem to be the ones in the middle of the pecking order. We are also noticing a decline in eggs. We were getting up to 6 a day about 2-3 months ago and now we are only getting 3, SOMETIMES 4 eggs. We've looked for mites but don't see any and there doesn't seem to be any sign of skin irritation or pecking/scabs. Also there weren't any piles of feathers, they just disappeared (maybe the girls ate them???). We did start mixing cat food in with their chicken feed (as an extra source of calcium) and now the girls love the cat food more than their own chicken food. Also just a quick note they are all around 1 year old, didn't molt in the fall. Here's the layout: alpha (barred rock): lost feathers 2nd in command (dark golden sexlink): lost feathers (not as much as the others though, at least not yet) 3rd in command (buff orp): lost feathers middle gal (light golden sexlink): has feathers the crazy one (wyandotte): has feathers (note: this one was brooding last week but has since stopped due to our intervention ((shutting her out of the nest boxes during the day for 3-4 days)).) omega (ameraucana): lost feathers (gets picked on a lot in general but can tell she has lost feathers in the same way as the others in addition to what the other girls peck off) Would pictures be helpful? We really love our girls but are worried! Is it molting? Mites (although we couldn't see any or find any in nestboxes/roosting pole)? Could it be the cat food???