Hey,
Don’t let it bother you. Archimedes does that too, especially when he does not want to be touched—I tend to ignore it though and pick him up anyways. This behavior could be a factor of many things, but I strongly believe it’s tied to territorial behavior.
When Archimedes was young, he would do the same exact stance and would pin his eyes. If I reached inside his cages he would nail me with a nice bite—which I ignored. Now, he’ll pin like that and just get on my finger without making a fuss. He knows what is expected of him. It’s really cool that you can see their emotions.
You dedication to your ringneck is astounding—keep up the work buddy!
Best wishes,
Imran