Have you ever 'surprised' your bird with your own hand? Like you were sitting watching tv with your bird on you and you either reached up to scratch your nose or take a drink of something and your bird gets surprised and nips your hand because he doesn't think of it as part of your body?
When I am sitting in my recliner and reclined back, my birds are drawn to my feet because I nervously twitch them while I watch tv. I have to make sure I keep socks on because if they see my toenails, they try to tear them off my toes. They are always surprised if I exclaim in pain when they bite my toes. My theory is that we have bodies that are so big compared to theirs that they do not understand those parts so far from the head and shoulders that they interact with are truly still part of our bodies. To our birds, we are a head, shoulders, arms, hands and a chest. Anything below the chest is not part of their idea of being part of us. I also noticed that in the winter when I have a blanket on for warmth while watching tv, if my hands come out from under the blanket and they don't see my arms, they don't understand they are MY hands and sometimes nip them as 'stranger' hands. Always makes me laugh.
One other thing I have observed is that my Senegal parrot and three of my cockatiels know that humans have two hands. If my bff or someone else reaches over my shoulder or around my body and the bird can see both my hands, they become afraid and will bite the 'third, stranger' hand!
Any of you ever see this? I was surprised when three of the tiels understood humans had two hands and that they could count to 3. Emmie CAG and Sunny Senegal can also count to three and I have known that for years. But the tiels surprised me.