Once you are infected, you can pass head lice to any close friend, or family member, whose head is in contact with your head. Head lice die if they are not kept warm. It is very unusual for lice to be found on hats, scarves, brushes or combs. They don't survive on pillows or towels. Really, the only way of catching them is to be in head to head contact with an infected person.
Head lice are very common.
In primary schools in the UK, probably one child in ten is infected every year. Young children tend to put their heads together, with friends or other family members, and lice are easily spread from person to person. The main symptom of head lice is terrible itching of the scalp. Children are more bothered with itching then adults. Infected children will scratch their heads vigorously, and will often scratch during their sleep.