General rule for getting ANY new animal, be it fish, Snake, Frog, bird, Ferret, puppy, whatever it may be, from a pet store: never, EVER, leave ANY question unanswered when you leave your house to get the animal. Never, EVER, rely on the store employees. Even if it's a good store with knowledgeable employees. I told this to a visitor while I was at work on saturday, we're not supposed to give advice on exotics pets (for some reason) but you should be able to write a book on an animal before you own it.
Of course this is an ideal situation, and everyone deviates from it at one point or another. But the bottom line is, dont ever leave any questions unanswered with the intentions of finding out the answer from a pet store employee.