I assume you don't have mites and are using PAM as a preventative. In that case you don't have to spray the bedding all the time. Even though PAM is suppost to be tested and safe it is still a pretty heavy toxin and you don't want to be exposing your snakes to it willy nilly. If you have no mites and you are not bringing in new stuff then you really have no reason to use it. If you want a preventative use proper quarantine procedures, don't take your snake around other snakes and when you bring new stuff in and take a shower and throw your clothed in the wash as soon as you get home from a reptile show. You could also hang a no pest strip in the room (not in the snakes cage) if you want and change it per the instructions.