What soes it mean when you dream your killing head lice?

First, remember that dreams often reflect our wishes, our hopes, or our fears. But just because you dream something, that does not mean it will happen. Dreams are fictional, even if they seem real and vivid when you recall them. Dreams may be about events you have experienced, or they may just be about things you are afraid could occur.

In the case of dreaming about lice in your hair, perhaps you encountered lice (in a news story or you knew somebody who had them) and that put the idea in your mind. Or perhaps it represents your fear that you are not clean in some way or that people will find out your terrible secret. In any event, I wouldn't worry. I doubt you really have lice, and if you ever do, there are medications to eradicate them.