My 3.5cm curly attacked my finger the other day when I lifted the bottlecap it hides under. Didn't bite, but jolted forward at me in an instant. It took it as a sign that it is hungry. so I think your theory might be correct.
I just added a hide and moved the water dish. It is already inspecting the hide.
But while adding it, whenever I touch the lid of the cage, it moved around very quickly. Like it is expecting to be attacked or something. It is very skittish, but I think it might calm down with something to hide in. Just hope he likes it.