Well, my take on it is that they do have different personalities, however limited. My balls, tolerate handling to various degrees, ranging from actively trying to explore to trying to bite anything moving because they want left alone. With my lizards and turtles it varies even more. I have 3 ackies in a cage, one dissapears the moment the door opens, one sits watching me warily, the last will practically come out to say hi, especially when food's involved. But the one common thing I take from all mine is that the interaction is more for my benefit than thiers. But that's ok by me.