Can't get rid of head lice?

I know it sounds weird, but coating your hair in mayo and wrapping it in plastic wrap always killed them when i was a kid. You shouldn't have to cut it off because the lice stay on the scalp, not in the hair. Be sure you clean your house, and see if anyone you have close contact to has the head lice cause you may be re-catching it from them. But its not just the lice you should worry about, its the eggs they lay close to the root of your hair. Even if you kill the lice, they can come back if the eggs aren't gone. If nothing helps then go see your doctor.