How do people contract lice in their hair?

From others: Using infected hairbrush or share the bed with someone, infected bed linen, or from close contact with infected hairs (school, hairdresser), etc.

Direct & indirect: Head lice are transmitted two ways. The most common is direct person to person contact. The second way is vector transmission – from a contaminated object to a person. Vector transmission occurs when lice are spread through inanimate objects. For instance the lice can be on brushes, combs, hats, headphones, scarves, sweaters, coats, bedding, towels, upholstered furniture, carpet or stuffed toys.