I also have ferrets and snakesI have to say ferrets are one of the sweetest furries I've ever owned, maybe I've just had some nasty pet cats... They never bite (some do I know) and always can make you laugh.
I agree they shouldn't be allowed near snakes because ferrets are possible of killing reptiles.
Ferrets are very good at getting out of cages so you should always have a lock of their cages just like your snakes. If you are responsible with your animals, these two, ferrets and snakes, should never have a reason to meet!