This irks me a lot. A LOT. As a mother who checks her kids's hair on a regular (some would say fanatic) basis, I just don't get why you would not even bother every once in a while. Some don't even care! I know, because I am acquainted with a few. That I keep my distance from. And I keep my KIDS a distance from.
What bothers me is when a note comes home from school saying 'a case of head lice has been detected, so please check your childrens' hair.' Which I do. But then another note comes home a week later. And again! Clearly someone (or many someones) is not following through.
Come on. It's not that hard. Just take a peek. If your child's hair looks like several communities of insects have moved in and are busy building skyscrapers, your child has lice. GET RID OF THEM FOR ALL OUR SAKES (especially mine, which hangs by a teeny tiny thread these days).