Risk Factors of LICE

For head lice, cleanliness and hygiene have little to do with getting infested. In fact it is believed that head lice prefer clean hair, as it is easier for them to lay their eggs. The biggest risk factor is your hair coming into contact with that of an infested person.
With crabs, studies have indicated that those who have other sexually transmitted diseases are more likely to have crabs as well. Having multiple sexual partners also increases the risk.

Body lice are more likely to infest a person who has poor personal hygiene or who lives in overcrowded conditions. Body lice are also known carriers of epidemic typhus, trench fever and louse-borne relapsing fever.