my chickens have lost all their feathers on their necks.

[budman57]

don't know if it is mites or something else. all info would be helpful.

 

[willowbranchfarm]

When chickens are molting, they lose their neck feathers first.

Here is an article I wrote on molting.
https://www.backyardchickens.com/a/chickens-loosing-feathers-managing-your-flocks-molt

If its not molting it could be rooster damage or mite/lice.