system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why isn't lice a problem in adulthood?

It seems like people had lice all the time in elementary school and then no one had lice once we were like 12. Why is that?
gpt
Headlice has nothing to do with hygiene. You can be the cleanest person on earth and still catch lice. 

The reason they spread more in younger kids, is because the kids play and tumble with each other, making it possible for the lice to spread from person to person. 

If a kid has lice for a few days undetected, the parents and possibly siblings are likely to get them as well. 

But because an adult is not as likely to go and rub their heads together with coworkers, no one at work gets lice. 
And so forth.