What is lice and how do you get it?

What is Lice and How Do You Get It?

Head lice are tiny parasites that feed on human blood and are found in hair on the head. The scientific name for head lice is Pediculus humanus capitis. Lice are wingless and cannot jump or fly; they can only walk or crawl from one person to another. Lice have been a problem for thousands of years, with evidence of their presence dating back to ancient Egypt. Children, especially those between 3 and 11 years old, are most commonly affected.

Types of Lice

There are three types of lice, and each type feeds on different parts of the body.

  • Head lice, as the name implies, infest the scalp and hair.
  • Body lice live on clothes and bedding, and only move onto the skin to feed.
  • Pubic lice, or “crabs,” are found in the pubic hair, but can also be found in hair on the legs, armpits, and even eyebrows and eyelashes.

How Lice are Spread

Lice are spread through direct head-to-head contact with someone who already has them. They can also be spread by sharing items such as hats, combs, brushes, and hair ties. It is important to note that lice do not discriminate and can be found in clean hair, dirty hair, long hair, short hair, and any ethnicity.

Signs of Lice Infestation

If you suspect that you or someone in your family has lice, there are several signs to look for:

  • Itching or tickling feeling on the scalp, neck, and ears.
  • Small, white or tan eggs (nits) on hair shafts close to the root.
  • Adult lice on the scalp or in hair.
  • Red bumps or sores on the scalp, neck, and shoulders from scratching.

Diagnosing Lice Infestation

If you suspect a lice infestation, it’s important to confirm the diagnosis with a healthcare provider. A healthcare provider can examine the scalp and hair for lice and eggs. They may also use a magnifying glass, comb, or flashlight to help with the diagnosis.

Treatment for Lice Infestation

If you are diagnosed with lice, it is important to begin treatment immediately. There are several treatment options available over-the-counter, including shampoos, creams, and lotions. These treatments work by suffocating or poisoning the lice and their eggs. It is important to follow the instructions carefully, and to repeat treatment a week later to ensure all lice and eggs are eliminated.

In some cases, prescription-strength treatments may be necessary. Your healthcare provider can provide you with a more in-depth examination and recommend the best course of treatment for your situation.

Preventing Lice Infestation

While lice can be a nuisance, there are several steps you can take to prevent infestation and spread:

  • Avoid direct head-to-head contact with others.
  • Avoid sharing items that come into contact with the hair, including hats, combs, and hair ties.
  • Avoid lying down on pillowcases, blankets, or carpets that have come into contact with someone who has lice.
  • Wash bedding, clothing, and other items that have come into contact with lice in hot water and dry on high heat for at least 30 minutes.


Lice infestations are a common problem, particularly in school-aged children. They are transmitted through direct head-to-head contact or sharing of personal items. Treatment is available over-the-counter or through prescription, and prevention involves avoiding sharing personal items and practicing good hygiene. While lice can be a nuisance, they can easily be treated and eradicated.

Most Common Questions and Their Answers

  • Q: Can lice fly or jump?
    • A: No, lice are wingless and cannot fly or jump. They can only crawl and walk from one person to another.
  • Q: Can lice live on pets?
    • A: No, lice are species-specific and can only survive on humans.
  • Q: How long do lice eggs take to hatch?
    • A: Lice eggs generally take 7-10 days to hatch.
  • Q: How do I prevent getting lice from someone who has it?
    • A: Avoid direct head-to-head contact, don’t share personal items such as hats and hair ties, and don’t lie on pillows that have been used by someone who has lice.
  • Q: Can lice survive in water?
    • A: Lice can hold their breath for up to 8 hours, but water kills them within seconds.


  • Araújo, A. R., Ferreira, F. C., Santos, T. D., &de Barros, Í. M. (2015). Pediculosis capitis: a practical approach for investigation and management. Infectious Diseases of Poverty, 4(1), 9. https://doi.org/10.1186/s40249-015-0041-y.
  • Center of Disease Control and Prevention. (2020). Head lice. https://www.cdc.gov/parasites/lice/head/index.html.
  • Frankowski, B. L., &Bocchini, J. A. (2010). Head lice. Pediatrics, 126(2), 392-403. https://doi.org/10.1542/peds.2010-1308.