I attempted to handle my BP last night (he's a year old and hasn't been handled in several months) while he was out and about in his tank. He curled up in a ball as usual, and this time I decided to just stroke him rather than lifting him out of the tank. After a couple of minutes of touching him gently I closed the cage. Almost immediately after the lid was shut he uncoiled and struck at me through the glass.
I find this very interesting since I wasn't moving around close to or in front of his head. It was like he turned around and realized that I am connected to the hands that pick him up, since my hands didn't seem to be his target.