Human Head Lice

Facts, Identification, & Control

Scientific Name

Pediculus humanus capitis


What Do They Look Like?
  • Size: Adults are about 1/8 inch long, about the size of a sesame seed and grey or tan colored. Nymphs are about 1/16-1/8 inch long, are grey or tan colored and look like a smaller version of an adult louse. Louse eggs measure about 1/16 of an inch.
  • Characteristics: Head lice are blood-sucking insects that live in human hair. Primarily found on the scalp, these wingless, six-legged pests do not live on pets.
  • Body: Head lice are flat and their legs have a claw that enables them to grasp hair shafts as they feed using their piercing-sucking mouthparts.
  • Color: Eggs look translucent, white, or yellow-brown.

How Did I Get Human Head Lice?

Because these pests cannot fly or jump, they rely on contact with infested hair to move between people. In many cases, the insects pass to a new host via clothes, hairbrushes, or bedding. Human head lice is typically spread between children and other family members. Head-to-head contact on playgrounds and sharing hats and hairbrushes is often the manner in which head lice are spread from one child to another and become the start of a head louse infestation. Head lice are not a condition that indicates poor sanitation or poverty since they can affect anyone.

How Serious Are Human Head Lice?

Do They Spread Disease?

Unlike body lice, human head lice are not known to spread diseases, but infestations are irritating and create a lot of alarm among family members. These pest’s movement and bites may also create an unpleasant itching sensation on the scalp, and scratching may result in sores or secondary bacterial infection that could possibly require treatment.

Although they are not transmitters of disease, they can cause extreme irritation, social stigma, and may also contribute to secondary bacterial infections that result from itching and sores in the scalp area. Getting rid of head lice requires several types of control.

Signs of Infestation

The presence of adult or juvenile head lice, eggs on hair shafts , itching and sores caused by scratching of the scalp are signs of a head lice infestation.

How Do I Get Rid of Head Lice?

What You Can Do

Lice can be removed manually with specially designed combs and can be treated with over-the counter or prescribed medications. Also laundering of all bedding and clothing using hot water and the hot setting on a clothes dryer will help reduce the chances of spreading head lice. Your pest management professional can provide important information and recommendations for head lice management; however, it is best to contact your family physician or another health professional should head lice become a problem.

For help with or more info on related pest infestations, give Orkin a call.

Bahavior, Diet, & Habit

What Do They Eat?

Head lice are parasitic on humans since they take blood meals by puncturing the skin and sucking blood several times a day.

Where Do They Live?

Head lice live on the skin among the hairs on the head. If someone is heavily infested, lice may be found in the eyebrows and eyelashes.

Geographic Range

Head lice are found throughout the United States.

Life Cycle

Lice appear in three life stages – eggs (nits), nymphs (juvenile adults) and adults. Adult female head lice normally produce 5-6 eggs per day for about 30 days. After hatching, lice go through the nymph stage where they molt three times before reaching adulthood.


Should a nymph or adult head louse become dislodged from their human host, they survive for only 1-2 days. This is because they are dependent upon the host for blood meals, moisture, and suitable warmth. While eggs may survive for up to three days off the human host, they do not hatch at temperatures lower than those near the scalp. Nits hatch about 5-10 days after being laid.

Head Lice & Dogs

Unlike fleas that affect canines, cats, rodents etc., human head lice cannot survive without a viable host on which to feed. Human head lice are endemic to humans and will not affect dogs, though other species of lice have been known to bite dogs.

Lice vs. Fleas

A flea infestation can easily be confused for a lice infestation. Fleas are pests which do affect dogs, and they infest homes and yards quickly. They may live within the carpet of a home for months before emerging as pests. Fleas, like lice, can bite humans, as well.

If your pet shows signs of excessive itching or restlessness, he or she may be harboring fleas. Be sure to clean all bedding and check for signs of flea infestations around your home. Should a flea infestation become evident, contact your pest control professional and veterinarian for treatment options.

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