Snake phobia is not without its uses. All you have to do is explain to the phobic how sweet and harmless the animal is, and how he just loves to cuddle with warm humans. Then tell them that the snake's name is Houdini and not to worry if he escapes at night and curls up with them, he's harmless and won't bite. Voila--no more unwanted house guests!
(Somebody--we need one of those evil smilie icons.)