Ferrets are part of the weasel family. Weasels are known snake killers. Did you ever see Rikki Tikki Tavi? Long story short weasel + snake = dead snake.
In all honesty, I would not let any animal near my snakes. (Except for feeding it, obviously)
there is no reason to do it, and too many chances/reasons not to. They do not get joy out of other animals, it would only be for our amusement that it "plays" with something. Just my 2¢