I have six hens and they are dealing with a couple of stress factors right now - it's recently gotten pretty cold up here (well below zero, some days high around zero, although it's been warmer some days) and they all moved into their new coop just over a month ago. Each bird has 10 square feet inside and they have plenty of unused roosting space (they all crowd together on the same roost.) The coop is dry and they are eating layer pellets, fresh water is available. While I was observing them yesterday I noticed that two of them are missing feathers around their neck, and they seem to have pin feathers growing in place of those (no exposed skin). I checked them for lice and didn't see any sign. Their vents and legs look good. These two aren't especially low on the pecking order (in fact one of them is the bossiest) and there is no bleeding or scabbing so I'm pretty sure they aren't having getting plucked by the other hens. Their poor featherless necks just look so awful and I'm worried now they'll get too cold. Everything I've read says hens don't molt until they are at least a year old. Could they be molting? Or is there something else happening?