missing neck feathers

[gmiller0789]

3 of my 9 chickens are missing almost all their neck feathers (see pictures below). I've never seen them fight or peck at each other and they're only 9 months so I don't think its molting. Is it mites/ lice?? Thanks for the help everyone!

 

[BirdsBeesTrees]

Do you have a rooster?

 

[gmiller0789]

Do you have a rooster?

No roosters

 

[Chicken poppy]

Less eggs? Is it fall?

 

[gmiller0789]

Less eggs? Is it fall?

Still almost an egg a day from each of them. We're in Missouri so it's nice and hot (early summer).