Pest profile

Body lice

Pediculus humanus humanus · Psocodea: Pediculidae[4]

Body lice are small insects that feed on human blood but live and lay their eggs on clothing and bedding. Unlike head lice, they can spread disease, and an infestation is usually cleared with regular bathing and hot-water laundering.[1][2]

Adult human body louse, a flat, elongated tan insect with six clawed legs, photographed from above on a pale pink background
Adult human body louse, a flat, elongated tan insect with six clawed legs, photographed from above on a pale pink background. (c) Christine Young, some rights reserved (CC BY) — via iNaturalist, CC BY 4.0

How to identify it

  • Adults are about 2.3 to 3.6 millimeters long, roughly the size of a sesame seed, tan to grayish-white, with six legs.[1]
  • Eggs, called nits, are tiny and easy to mistake for dandruff; they are laid in clothing and bedding rather than on the skin.[1]
  • Newly hatched nymphs are about the size of a pinhead.[1]

Look-alikes

Look-alikeHow to tell them apart
Head liceHead lice live mostly on the head, eyebrows and eyelashes and don't spread disease; body lice live in clothing and bedding and can spread disease.[2][1]

Where it lives

Body lice occur worldwide but are concentrated where people live in crowded conditions without regular access to bathing and clean clothes.[1]

Biology and life cycle

Nits hatch in about 6 to 9 days, and the nymphs grow into adults in about a week.[1]

A female can lay up to eight nits a day.[1]

Adults need to feed on blood several times a day and die within 1 to 2 days if they can't feed.[1]

Damage and signs

  • Infestations mostly affect people without regular access to bathing and clean clothing, such as people experiencing homelessness, refugees and disaster survivors.[1]

Health risk

Body lice can spread epidemic typhus, Bartonella quintana infection and epidemic relapsing fever; bites cause intense itching and rash, and long-term infestations thicken and darken the skin.[1][3]

Control

Prevention

Avoid sharing clothing, bedding and other personal items.[1]

Sanitation

Bathe regularly and change into clean clothes at least once a week; better hygiene is the main treatment for body lice.[1]

Machine-wash infested clothing and bedding in water at least 130 degrees Fahrenheit, then dry them on high heat.[1]

Dry-clean items that can't be washed, or seal them in a plastic bag for two weeks.[1]

Pesticides

Lice-killing medicines exist but usually aren't needed when hygiene and laundering are kept up; insecticide dusting is sometimes used to control disease outbreaks.[1]

How body lice spread

They spread through direct contact with a person who has body lice, or through infested clothing, bedding or linens.[1]

Epidemic typhus, also called louse-borne typhus, spreads to people through contact with infected body lice.[3]

Pets do not spread human lice.[1]

Common questions

What water temperature kills body lice?
The CDC advises washing infested items in water at least 130 degrees Fahrenheit and drying them on the hot cycle.[1]
Can I get body lice from my dog or cat?
No. Pets don't spread human lice.[1]
Do I need medicine for body lice?
Usually not. Regular bathing, clean clothes and hot-water laundering of clothing and bedding are normally enough.[1]

Sources

  1. U.S. Centers for Disease Control and Prevention, “About Body Lice (updated June 24, 2024).” www.cdc.gov/lice/about/body-lice.html (accessed 2026-10-06)
  2. U.S. Centers for Disease Control and Prevention, “About Head Lice.” www.cdc.gov/lice/about/head-lice.html (accessed 2026-10-06)
  3. U.S. Centers for Disease Control and Prevention, “Typhus Fevers Basics (updated December 11, 2025).” www.cdc.gov/typhus/about/index.html (accessed 2026-10-06)
  4. iNaturalist, “Pediculus humanus humanus taxon page (order and family).” www.inaturalist.org/taxa/411752 (accessed 2026-10-06)

Updated 2026-10-06. Built from sourced records. Spot an error? Tell us.