Hi there - new to chickens here - About 4 of my 9 hens are all missing feathers on their backs right before their tails - you can sort of see in this terrible photo... We thought they were just moulting but the feathers don't seem to be growing back. Then we thought the rooster is pulling them out - when he jumps them that's where his feet are... But after googling I saw that sometimes missing back feathers could be mites? Any help would be really appreciated!! PS don't mins this make shift fence tunnel - it's a run to a bigger area for them.