Of course they shouldn't. But they do. Not so much "rummaging" although I'm sure that happens, too, but they certainly open cabinets and drawers. Its almost like they feel entitled to know everything about the house they may buy.
I would rather people KNOW whats in that "drawer" and leave it alone, rather then someone's curiosity getting the best of them and opening a drawer. Even someone without a snake phobia would probably have half a heart attack if a snake came at them. Just not something you expect
I'd be afraid someone opened a drawer (tub), jumped away, took off and the snake gets out never to be found again. Plus that wouldn't exactly help the sale, either (loose snake in house).