Large hard lumps on chicken neck?

[Thrusday]

My 8 week old naked neck has these large hard lumps on her neck. I haven’t noticed any chickens pecking her so I don’t think it’s pecking. I thought for a moment they may be botflies but I don’t see air holes on the lumps. They have grown noticeabley over the past 2 days.
Does anyone know what these might be and how to treat them? None of the other chickens have anything like this, she’s the only one with these lumps...
(We live on 18 acres in Oklahoma and half the land is wooded. I let my chickens out to free range all day throughout the property.)

 

[Eggcessive]

I am not really sure what that is, but could it be a warble fly bite with larvae or maggots? I would try something like SWAT, a piperonyl/pyrethrin ointment for horses to kill and smother any flies and larvae. The other guess would be peck wounds. Hopefully others will know for sure what is going on.