Head lice spread quickly through direct head-to-head contact. They are more common in children, spreading easily in group settings such as preschool or elementary school.

A head louse, or Pediculus humanus capitis, is a tiny, wingless parasite that attaches to a person’s hair and feeds on their blood. Head lice live their entire life cycles on an individual’s head, particularly on the scalp near the neckline and the ears.

These parasites cannot fly, jump, or hop. They can only crawl and primarily spread through head-to-head contact. This type of contact commonly occurs in children during play at school, sleepovers, and sports activities. Less frequently, a person can get lice from sharing clothing and other personal items with someone who has lice.

This article explores how contagious lice are and how to prevent lice from spreading. It also answers some common questions about them.

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The Centers for Disease Control and Prevention (CDC) estimates that around 6–12 million head lice infestations occur every year in the United States. The organization adds that head lice are less common among African Americans than among people of other races.

Learn more about head lice and coily hair.

In most high income countries, the occurrence of head lice is relatively low. Head lice primarily affect certain groups, such as:

  • school children
  • refugees
  • people experiencing homelessness

According to a 2016 study, head lice infestation most commonly affects children between the ages of 4 and 12. This includes preschool and elementary-age children. Head lice can also spread to a child’s caregivers and anyone else they may closely interact with, such as older siblings or other family members.

The authors of the same study also suggested that lice have associations with darker and longer hair. Meanwhile, another 2016 study found that having shorter hair cuts the risk of contracting lice by about 50%.

An older study from 2015 also found that lice were more common among children:

  • with parents with lower education levels
  • with long hair
  • from families with more members
  • with caregivers who spent more time in the home
  • using shared combs
  • with less access to bathrooms
  • who bathed less frequently at home

The authors of the study also found that girls are 5.5 times more likely to contract lice than boys.

The CDC notes that head lice do not indicate that a person or their environment is dirty or unhygienic. Anyone can get head lice, regardless of their living situation or how often they bathe or shower.

Discover the causes of head lice.

Other ways to prevent and control the spread of lice include:

  • avoiding hair-to-hair contact during play and other activities
  • not sharing clothing, such as hats and hair ribbons, and personal items such as towels and combs
  • soaking any brushes and combs a person with lice may have used in water that is at least 130°F (54.4°C) for 5–10 minutes
  • avoiding sitting or lying on couches, pillows, and beds that a person with lice has been in contact with
  • machine washing and drying all clothing or bedsheets someone with lice has used in the 2 days before they have had lice treatment in 130°F (54.4°C) water and a high-heat drying cycle
  • dry cleaning all clothing or bedsheets that are not washable or sealing them in a plastic bag for 2 weeks
  • vacuuming the floor and any furniture where a person with lice has sat or laid down

People do not need to use fumigant sprays and fog to control head lice. These chemicals can be toxic for individuals if they inhale them or absorb them through the skin.

Caregivers also need to ensure they treat children with head lice promptly. They can also regularly inspect their children’s hair to help detect and treat head lice infestations early.

Learn more about effective ways to get rid of lice.

Below are some of the most common questions about lice.

How do lice spread?

Head lice cannot hop, jump or fly. They spread by crawling primarily through direct head-to-head contact.

Children most commonly contract lice during play and other activities. Less frequently, individuals spread lice when they share or come into contact with clothes and personal items a person with lice has used.

Can someone get lice from a hug?

It is unlikely for someone to get lice from a quick hug. However, someone is more likely to contract lice from having head-to-head or hair-to-hair contact with another with head lice. This type of contact may happen when people hug.

Why do children get lice?

Anyone can get head lice. However, children are more likely to get head lice due to their tendency for close contact and physical play with other children. Head lice primarily spread through direct head-to-head and hair-to-hair contact, which children may engage in during play.

Head lice can spread quickly from person to person through head-to-head contact. Younger children are especially prone to head lice.

People may prevent the spreading of lice in a number of ways. For example, they may avoid head-to-head contact and sharing personal items, such as towels and combs, that a person with lice has used.

Caregivers who think their child may have lice can contact a healthcare professional for advice about treatment options.