Answer:
The benefits of parasites such as lice have a role in the conditioning of a 'natural' immune system and reducing the likelihood of immune dysfunctions, a study of mice from a Nottinghamshire forest indicates.
Head lice are not actually harmful and they don't spread disease. They're not a sign of poor hygiene — head lice need blood and they don't care whether it's from someone who's clean or dirty.
Explanation:
base on my research
