While head lice spend most of their time on the head of their hosts, some species can survive off the head for a short period of time. These bugs live on a hairy surface, such as the scalp, and feed on the blood of their hosts. Human head hair acts as an insulator and is a perfect place for them to lay their eggs. Even if you do not have a pet, you are still likely to contract head lice if you come in contact with an infested person.
Once a head lice has been removed from its host, it will usually perish. However, some types of lice can survive off the head for a day or more without feeding. Adult lice can survive for a day or two without feeding, while young lice may only survive a few hours. Lice nits will also generally die after a week. This is because they cannot survive in temperatures below the scalp. In case you accidentally come into contact with a head lice sufferer, you should use a preventative treatment.
Head lice are not difficult to spread from person to person. The most common way they spread is through head-to-head contact. This occurs during play, sports activities, and slumber parties. Even lying on the same bed with an infected person can spread the infection. However, pets do not play a role in spreading head lice.