I picked sometimes. For me, the head poking out is inquisitiveness on what just came into my room. And the climbing up my hand is the fact that I happened to catch them in an active mood. They won't necessarily always "curl around my hand" lol, but they'll explore up my wrist and come out. Same with my dumeril's. It depends on if I catch them feeling active, whether it's hunger or not.
BP's, by nature and biology, aren't social animals. There ARE other social species of snakes (like rattlesnakes, garter snakes). So that's not the right term for BP's. But nobody said they can't be curious and inquisitive and active once in awhile, especially at night.