Provent-a-Mite is generally only used for mites on snakes and for use in their enclosures. It will kill fleas as it is a pesticide, but I wouldn't put it all over your house.
I strongly suggest you use Frontline Plus or perhaps Advantix for your dog. It's very easy to use and safe. It's not the cheapest thing, but it is the best and your dog will thank you for it. I don't recommend any other top-spot treatments as the other products out there are not as safe. Sentinal, which is given orally to the dog (chewable tablet) is another good product as well although it should be given in conjunction with a top-spot treatment such as Frontline Plus.
Frontline Plus will kill fleas for up to 3 months although if you have sandy soil or live in an area with lots of squirrels or rabbits, you could give it as often as every month throughout the summer and fall. Start now or within the next month to prevent a home infestation. The beauty is than none of these products come anywhere near your snakes - they are used only on the dog. So there is absolutely no danger to your reptiles.
I raise German Shepherds. My dogs have traveled all over the state to various shows and trials and they've been exposed to a lot. I also teach obedience classes for our local kennel club and they're exposed to a lot there too. We have sandy soil and live in the country practically overrun with rabbits. Sounds like a recipe for a flea disaster! I use Frontline Plus on all 6 of my dogs every other month from the 1st of May through November. We've never had a single flea. It works.
It most certainly does kill fleas, the pesticide active ingredient is found it all flea sprays and house bombs. ITs expensive to use but does work as ive done it