trantran

I've had my grey for about 2 years now. I've never followed any professional steps in order to tame him, but I did manage to succeed to some extent. I had moved out of the house, however, for a year, but when I returned, my grey surely remembered me. I've been spending more time with him lately, including walking around the block with him on my arm. I don't think he has flown before, but he did get scared by the fence gate opening to close to him yesterday and took off, flying across my backyard at a low altitude and eventually into the fence. He seemed totally fine, so I just picked him up and continued on. Today I decided to start some clicker training with him. First thing I wanted to do was be able to hold him on his back. He allows me to pet him all over and pick him up in the "bat" position so I felt he was ready. I started out very slowly, with one hand on his back while rotating him to the upside down position. First try went pretty well, as I successfully rotated him over on his back. I did notice that his feet were still holding on to my hand as if there were no tomorrow (fear?). So then I followed to reward him with a click and a treat. Time for a second try. I did the same exact thing, except this time, he started striking at me and biting me about halfway through. He definitely is a nibbler and continuously nibbles on my fingers as I pet him and sometimes he starts nibbling just a tad bit too hard, but it becomes clearly noticeable when he attacks, as he also launches his head with the bite just like every other bird. He still has yet to shed blood on me, though, nor do these bites leave any sort of lingering pain afterwards. As a bad habit, every time he does this (he use to a lot when he would get scared of something) I accidentally tend to drop him out of my own fear as I feel the bites getting harder and harder. It usually isn't a far drop though, probably only 2-3 feet, and definitely not intentional. After he's on the floor, though, he'll willingly hop right back onto my hand without any problem. I'm assuming he did not like going upside down which caused him to bite me and let me know. How can this be fixed? And also, though he has not shed any blood on me yet, is there a possibility he would? Or does he trust me enough to only give me a "warning" bite? I've never been to that point so I wouldn't know.