Do you have a roo? Roosters grab onto the hen's head during the mating process. If not, check for mites, fleas or lice. You can lift up feathers and look on their skin and on the feather shaft to see if they do.
If you suspect mites, fleas, or lice, let us know and we can walk you through the process of eliminating them.
Sure, treat them anyway. They could be molting, but treating them with Poultry Dust won't hurt.
You can find Poultry Dust at the feed store. The directions are on the container. Dust them really well and make sure they have an area to dust bathe in. That is their natural defense against bugs.
Ok, I just wanted to update my findings. I was able to catch about six of my chickens and check for bugs. Nothing, not a one. So I sat outside with them for a few hours(finally a nice day in Minnesota) to observe them. I think a few of my hens are having gender issues. They, 3 of them, are mounting the other birds like, you know, and pulling all their feathers out! Has anyone else had this problem? How do I get them to stop?