these things are said to have become immune to expensive medical, pharmacy treatments, etc., etc., i have not been able
to rid myself
of them for almost a year now. I wear a shaved, or short hair style and they are still surviving though I have tried RID (does not work!) it only increased them.
The internet has many sites that say natural methods like mayonnaise, vinegar, and natural oils can be used to smother the louses and neutralize the nits.