My chickens are losing feathers straight down their chest, and it isn't molting. They seem great otherwise, and I don't see any lice eggs. Maybe mites? They are only losing feathers on the spot they lay down on, so maybe the feathers are just getting worn out? I can't find any information on Google, so I really need some advice. I just put fresh shavings in their coop today, so maybe that will help. They've only been doing this for a week and a half, but the condition is worsening. Has anyone had this happen to their chickens? Thanks for your help!