I'm getting a clearer idea of what's going on with Diane Ida-Biter and she's beginning to understand biting and hard pecking is not okay. I think her inner drives are very intense, she's both super food-oriented and very focused on me, much more than the other two Spuds. She's learning the boundaries and I can see (and hear in her vocalizations) how hard it is for her to resist her urge to peck to get what she wants. She still needs a reminder from me every day, always vocally and sometimes restraining her when that fails. She's battling her instinct to bite hard against her fear of discipline from me if she does (I warn her vocally, then with my finger raised, then peck her with it if she persists, then hold her down tipped on her side or hold her firmly under my arm if she fights me).
Lately her bites have been relatively gentle, no blood drawn and usually no bruising even but that's still not okay to go for my hands. She's allowed to preen my clothes and get dust bits off me, eat snow off my boots, and beak my pants just to hear the zippy sound it makes, undo seams and pull on threads and whatnot, climb on my back and shoulders and explore whatever, just nothing hard directed at my hands or bare skin.
They might be learning. Yesterday there was a group of them lightly pecking, pulling and exploring my lower back clothes as I crouched, and there must have been a bit of skin showing and I got a sharp peck back there. It wasn't too hard but their beaks are sharp! I yelped and jerked a bit, and suddenly it all stopped for a couple seconds. I didn't move further and everything resumed, but nobody pecked that spot again. Progress?