From Everything we read about them, they can not be transferred from Human to Ferret. They are human lice, and will stay on a human as long as they are available. The ones you will find on the bedding or floors are usually dying or will die. They can not live off a host for very long either. Just continue to do what you do, if you get the dreaded letter or call. Spay the home with Nix, do the kid's heads, wash the bedding. Run the cleaner really well, spray the bag and get rid of it right away. Please remove the ferrets from the room you are spraying as for the Nix is very toxic and could be too strong for the ferrets. (M) [Posted in FML issue 4606]