I cant speak for cornsnakes, but as far as balls, the answer is simple!

It depends



Sometimes they are scared and stay curled up in a ball in your hands, sometimes they just HAVE to be anywhere BUT in your hands, sometimes they will explore your arms and neck, sometimes they will go up your sleeve, sometimes they will just curl around your arm and stay there.

Depends on the snake, depends on their mood, depends on a lot of things As long as you realize they are the boss, and they will do what they want to do when they want to, then everyone will get along fine