Headlice were a permanent feature of our lives for about three years, with school-age kids where they constantly do the rounds. Prior to that, I'd picked them up when I was volunteering in an orphanage in Kathmandu (and they were massive buggers) and then I had the joy of de-licing my daughter after she had been teaching English to kids in Italy for two months. They are the worst but I do feel like a master now at the job.