Frequently Asked Questions

Head lice are tiny insects that live close to the scalp and feed on human blood. Head lice are found most often on the back of the neck and behind the ears. For more information on headlice and superlice, check our what are head lice page.

Head lice and superlice cannot jump or fly, but they CAN spread very easily from person to person through close contact or through shared clothing or personal items (hats, towels, or hairbrushes). Learn more about how to prevent head lice here.

Though the thought of having a child with head lice can certainly leave you feeling anxious, keep calm and Nix® on. Head lice are extremely common, and also very easy to treat. They’re found worldwide, mostly in preschool and elementary school-age children. An estimated 6 to 12 million infestations of lice occur each year in the United States alone.

To understand how to identify lice, it helps to know the three different forms of head lice:

Eggs (nits): Nits are oval-shaped lice eggs that attach themselves to the hair shaft. They are hard to see with the naked eye, as they’re only about as large as a knot in a piece of thread. Usually white or yellow in color, they are often confused with dandruff or scabs. Nits usually take about 8-9 days to hatch. Eggs that are likely to hatch are usually located very close to the base of the hair shaft.

Nymph: A nymph is an immature louse (singular of lice) that hatches from the nit. It takes about 9-12 days for a nymph to mature into an adult.

Adult louse: An adult louse is about the size of a sesame seed, has six legs, and is tan to grayish-white in color. An adult louse, which must feed on blood in order to live, can survive up to 30 days on a person’s head but will die within one or two days if it falls off a person.

The most common (and annoying!) symptom associated with head lice is itching, although it may take some time for symptoms to develop.

Head lice can usually be detected by looking closely for live lice or eggs in the hair. Use a magnifying glass to help you search. If you’re not sure whether your child has head lice, ask a school nurse or other health care provider to conduct a thorough search. For more information, check our what are head lice page.

Head lice survive less than 1-2 days if they fall off a person and cannot feed. Nits usually die within a week if they’re not kept at the same temperature found close to the human scalp.

Some people think only “dirty kids” get head lice. NOT TRUE! Lice are attracted to blood, not to dirty hair. Personal hygiene or cleanliness in the home has absolutely nothing to do with getting head lice.

Dogs, cats, and other pets don’t spread lice. Lice pass from person to person through close contact with the hair or personal items of a person with head lice. 

Although head lice can cause symptoms such as itching or scalp sores, they have not been shown to spread disease. They are thought to be more a nuisance than a health hazard.

Head lice can hold tightly to human hair, even when submerged under water. Chlorine found in pool water does not kill head lice.

Lice cannot jump or fly. They can only crawl. They pass from person to person only through contact, either directly or through the exchange of a personal item such as a brush, comb, or hat.  For more information on head lice and superlice, check our how to prevent head lice page.

Unfortunately, the louse itself is not the only problem for someone with head lice. The eggs, or nits, must also be killed. Nits will hatch after about 7-10 days and must be removed.  Once no lice are present, use Nix® Lice Prevention Spray every day before school or camp for long lasting protection or to protect the whole family when a family member has head lice. Check out our How to Prevent Lice page for more information.

Superlice are becoming more likely given they are the dominant species of lice in the United States. Superlice are head lice that have genetically mutated to become resistant to the active ingredients in some traditional lice treatment products. Superlice do not look any different from regular lice and they can only be identified by their resistance to traditional lice treatments.

Since it is impossible to tell by looking at them, if you are not sure what type of lice you have, we recommend purchasing a product that kills superlice, like Nix Ultra® All-in-One Shampoo to minimize the need of re-treating. For more information on lice, visit our What Are Head Lice? page.

Some tips to protect your child from getting head lice include: avoiding direct head-to-head contact with others; not sharing clothing or personal items; separating clothing; and cleaning items that have come into contact with a person infested with head lice in hot water (130° F) and then drying the items in the dryer on a high heat setting.

No need to get out the scissors just yet! While shaving your child’s head can help solve the problem, it’s a drastic and unnecessary measure since so many effective treatments such as Nix® Lice Treatment products are available!

In truth, all pediculicide (lice-killing) products available today are susceptible to resistance. Nix^® does have a residual effect. This means that some residual or lingering activity of Nix^® remains on the hair for up to two weeks, even with regular shampooing. This residual activity allows Nix^® to kill lice—including baby lice as they hatch—and protect against lice reinfestation for up to 14 days. Products with longer residual effects tend to be more effective in killing lice eggs.1

Reference: 1. Mazurek CM, Lee NP. How to manage head lice. West J Med. 2000 May; 172(5): 342–345.

Very! This is the critical step to remove the nits and lice to make sure they are all removed. The process can be made easier if hair is separated into sections to comb through. It is also very important to remember to wipe the comb after each pass through and place any lice or nits into a sealable plastic bag for disposal. Please check our how to treat page for more information.

There are two reasons this may be happening. The first is a nit or louse may have been missed during the comb out process. The second reason is it is possible you are dealing with superlice, the dominant species of lice in the United States that are resistant to pesticides. We recommend retreating with Nix Ultra® All-in-One Shampoo.

We recommend one treatment with either the Nix Ultra Hair Treatment Solution or Nix Ultra All-in-One Shampoo when lice are present and recheck after 7 days. If lice or nits are still present after 7 days, another round of treatment is suggested. Check out our how to treat page for more information.

When lice are no longer present, use Nix® Lice Prevention Spray daily to keep lice away. The number of  sprays per application will vary with hair length and thickness. Spray liberally onto washed towel-dried hair or dry hair up to two times daily.

In truth, all pediculicide (lice-killing) products available today are susceptible to resistance. Nix^® does have a residual effect. This means that some residual or lingering activity of Nix^® remains on the hair for up to two weeks, even with regular shampooing. This residual activity allows Nix^® to kill lice—including baby lice as they hatch—and protect against lice reinfestation for up to 14 days. Products with longer residual effects tend to be more effective in killing lice eggs.1

Reference: 1. Mazurek CM, Lee NP. How to manage head lice. West J Med. 2000 May; 172(5): 342–345.

There are two reasons this may be happening. The first is a nit or louse may have been missed during the comb out process. The second reason is it is possible you are dealing with superlice, the dominant species of lice in the United States that are resistant to pesticides. We recommend retreating with Nix Ultra® All-in-One Shampoo.

We recommend one treatment with either the Nix Ultra Hair Treatment Solution or Nix Ultra All-in-One Shampoo when lice are present and recheck after 7 days. If lice or nits are still present after 7 days, another round of treatment is suggested. Check out our how to treat page for more information.

When lice are no longer present, use Nix® Lice Prevention Spray daily to keep lice away. The number of  sprays per application will vary with hair length and thickness. Spray liberally onto washed towel-dried hair or dry hair up to two times daily.