Feathers missing at neck- lice or mites or pecking??

[tmann14]

I have a 1 yr old RIR that recently has developed a bald patch on her neck. She is a scissor beak and the low hen.in the pecking order of only 3 hens. My other australorp is very jealous of her, soni just assumed it was her pulling my RIR's feathers, but then I started reading about mites and lice and I didn't wanted to overlook a problem, if there was one. I checked her vent and all seemed clear of bugs. There are no pin feathers at the bald spot, but also no sign of lice, that I could see. She does appear to have white dandruff?? Could this really be feather pulling or something else?

 

[sourland]

Sounds like feather pecking/plucking to me.