I looked at the Snopes info on this. They can say what they want but I will not dismiss the fact that I did have a friend who's cat did get ill after they started using this product on their floors (vomiting and lethargic). That is enough proof to me that it is at least harmful enough to make animals sick if they are exposed to it often enough whether or not it could kill. The cat was fine when they discontinued use. If I had a indoor pet, I certainly would not be using this product at all!