How do head lice spread from one person to another?

Head lice are small, wingless parasitic insects that primarily spread from one host to another through direct contact.12

Unlike some other pests, head lice are specialized to attach themselves to human hair or the scalp using claws on their legs. Because they cannot fly or jump, they rely on this close physical interaction to move between individuals. Once an infestation occurs, it can cause intense skin irritation, and the resulting scratching may lead to secondary infections. While hygiene practices like using a fine-tooth comb are recommended for control, head lice have shown increasing resistance to many common insecticidal shampoos, leading to a resurgence in various parts of the world.12