Lice have evolved. The chemicals and pesticides that killed a louse 50 years ago barely make a dent today. It’s called “pesticide resistance”.
Even just the mention of the word “lice” makes people itch. A lot.
You may not know this, but I am also the Lead Pastor at a local church (The Village Church of Bartlett) which means I preach in front of hundreds of people weekly or more. Every time I say the word “lice” in a sermon, people just start itching their head. For minutes.