Head lice becomes big news in the fall when schools and day cares begin a new year. This article I read in the CBC news online states that head lice have developed a resistance to all the chemical over the counter treatments, very much like bacteria has.
There are natural and safe treatments for lice that work just as well. Here is a link to my web page on treatment, which I gathered up a few years ago:
http://torontohomeopath.ca/natural-treatment-for-head-lice
Here is the link for the CBC article: