How old are they? When their adult feathers begin to come in, they can often be itchy and irritable. If their down and feathers are otherwise OK looking, it could just be that or itchy dry skin.
Hey,
They're a month old tomorrow, I have 2 boys and a girl (I'm swapping one of my boys for a girl back to my breeder tomorrow) both boys already have tail feather stalks or 'toilet roll tubes' as I call them ha. They seem happy and healthy, skin isn't red or scabby, I think it would really show if they have mites...?