Head Lice Fast Facts
- Adults are small (1/16–1/8-inch long), wingless and brown-colored. They have pincher-like claws which help them firmly grasp human hair. Lice feed on blood.
- Head lice develop in three stages: egg, nymph and adult. Female lice lay 8–10 eggs a day, eggs hatch in seven days and mature to an adult in another seven days. Lice live for about 30 days.
- Lice do not jump, fly or crawl long distances.
- Head lice are transmitted through head-to-head contact or immediate sharing of items like hats, combs or headphones.
- There are several products that help to control head lice but you may have to use multiple products multiple times to completely remedy the issue.
How are Head Lice Transmitted?
Transmission occurs through close, head-to-head contact, such as hugging, immediate hat or headphone sharing, sharing hair brushes or costume sharing, or sharing a bed or pillow. Lice do not live or breed on inanimate objects or other animals besides human heads. Even items in contact with head lice such as clothes, hats, headphones, blankets, rugs, etc. will have a low risk of transmitting head lice after 24–48 hours of non-use.
How Can I Tell if my Child has Head Lice?
An active infestation of head lice is defined as live, moving and feeding individuals. To inspect your child’s head, you will need: a bright light, a comb and a magnifying glass. Have your child sit in a chair and comb the hair, close to the scalp, to inspect for adult lice or their eggs.
What you are looking for:
Viable eggs — Eggs (aka nits) are less than 1/32-inch long, light brown/yellow/white, oval-shaped, and are glued to one side of the hair shaft. Lice eggs are located no more than 1/4 inch from the scalp and are common at the nape of the neck and close to ears. Hatched eggs are pearly white and remain attached to the hair. Due to hair growth over time, nits are considered non-viable if found 1/4–1/2-inch from the scalp.
Adults — Adult lice are 1/16–1/8-inch long, wingless, brown-colored insects. They have pincher-like claws allowing them to firmly grasp hair shaft.
Other symptoms of an active case of head lice include tickling sensations, difficulty sleeping, rashes from scratching and an itchy scalp. Make sure the problem is, in fact, head lice and not dandruff, sand, dirt or hairspray.
How do I Treat for Head Lice?
Mechanical treatment includes combing hair with a fine-toothed, metal comb to remove viable nits and lice, repeated every few days for at least two weeks. In addition, there is a variety of FDA-approved pediculicides (lice killers) sold over-the-counter or as a prescription treatment (see table here). These products are safe and effective when used as directed.
Be sure to follow directions. Some require a second treatment to kill new nymphs because most pediculicides cannot penetrate eggs. Abide the warnings of minimum age, potential allergic reactions, amount of product and time pediculicide remains on scalp — more is not better.
Objects such as brushes, combs and ponytail holders in contact 24–48 hours prior to treatment can be washed, soaked and dried in temperatures greater than 130°F to kill all stages of lice. Sheets can be laundered in hot water. Upholstery and carpets can be vacuumed — be sure to practice proper vacuum management (i.e. empty and wash canister or discard bag). To protect children from unnecessary pesticide exposure, insecticide sprays are not recommended for objects in the home.
Are There any Natural Remedies to Protect my Head from Head Lice?
There are no scientifically proven preventative treatments or protective shields to protect one’s scalp from head lice. We do not recommend any home remedies posted on the internet. They may irritate the scalp and skin, damage hair and have little to no effect on head lice.
What are the Reasons our Household Struggles to Control Head Lice?
Some reasons for ineffective lice treatment are misdiagnosis, improper treatment, lack of thoroughness, insecticide resistance and repeated reinfestation.
Treatment with pediculicides must be methodical and thorough, following the directions included with the product to break the louse life cycle. Performing a pediculicide hair treatment combined with combing, will kill and physically remove lice and nits.
Check heads periodically and treat all family members with active lice at the same time to prevent reinfestation between treated and contagious members. Treating heads with pediculicides when no live lice are present will not deter or kill lice at a later time, and only exposes individuals to unnecessary insecticides.
If lice are a persistent problem in your family, consider who and what activities may be the source of the active infestation. Discourage close head-to-head contact with other children and sharing personal items such as brushes, caps, headphones and pillows. Launder and dry linens and clothes, vacuum carpeting and bag any items that cannot be laundered.
Authors:
Jody Green, Ph.D., Urban Entomology Extension Educator, Nebraska Extension in Douglas-Sarpy Counties
Jonathan Larson, Ph.D., former Urban Entomology Extension Educator, Nebraska Extension in Douglas-Sarpy Counties
For more information, contact your state's local Extension office. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the University of Nebraska–Lincoln is implied.