I have been struck at and nailed but never got a hold of me and let go right away. Granted she is a WC parietalis, she was picked up so young that she still has the ability to adapt, and I think you're right about handling them, they need to know your presence is trustworthy and that you are not a predator, and they aren't your prey. I think once this trust is established they become a little more bold around you but still have the tendency to get scared and strike from reflex. If you place a piece of night crawler in your hand and coax them to come onto your hand a little bit then eat it, It might make them more trusting of you, then again it might get you eaten alive!