Information about Head Lice




Head lice cause unnecessary absence from school and work, millions of dollars misspent on remedies, and unnecessary treatment of misdiagnosed infestations.


Studies demonstrate that screening for head lice in schools does not decrease the incidence of head lice and is not cost effective. Results of studies suggest that education of parents in identifying and managing head lice is more effective and that class-wide or school-wide screening should be discouraged.

The American Academy of Pediatrics, the National Association of School Nurses, the Centers for Disease Control and the NH Dept. of Health and Human Services have all recommended that students with nits and/or head lice infestation not be excluded from school.


The Conval School District does not endorse or recommend any product, process or services. It is not the intent of the Conval School District to provide specific medical advice but rather provide users with information to better understand the treatment of head lice. Specific medical advice cannot be provided and the Conval School District urges you to consult with a qualified health care provider for diagnosis.

The Conval School District is not responsible for the availability or content of the external web site links nor does the Conval School District endorse, warrant or guarantee the products, service, or information described or offered at these Internet sites.

Prepared by the Conval School District School Nurses.

Updated March 21, 2011

For more information:


  1. What are head lice?
  2. Head lice are insects about the size of sesame seeds, about 1/8thinch long, that only

live on human heads. Their color can vary from gray to dark brown. Their food source is human blood. The presence of head lice is not due to lack of

hygiene or cleanliness of the home.  Head lice actually prefer clean long hair.


  1. What are nits?
  2. A nit is a teardrop shaped egg that is cemented to one side of the hair shaft about 1/4

inch from the scalp. A female louse can lay 6 – 8 nits a day. Nits hatch in 12 days into a nymph.  The nymphs

immediately begin feeding on the human head and become adult lice in 9 – 12 days.


  1. How long do lice live?
  2. Adult lice live up to 30 days. Head lice usually survive for less than one day away from the scalp. Their eggs cannot hatch at a temperature lower than that near the scalp.


  1. How do I get head lice?
  2. Head lice are wingless. They cannot hop, jump or fly. Head lice cling to hair and are mostly transmitted by direct head to head contact. Transmission by shared combs, brushes, hats, and helmets is not likely.


  1. How do I know if my child has head lice?
  2. The best way is to find a live louse on the head. This can be difficult as they move extremely fast. The nits may be easier to spot at the nape of the neck, behind the ears, and on the crown of the head. Scratching may be noticed. However, the first time a person is infested, scratching may not be evident.



  1. How do I treat a head lice infestation?
  2. The ConVal school district does not endorse any particular treatment. Some treatment options for school age children include:


  • Pediculocides – shampoos with There is some evidence that the lice may become resistant to these. Pediculocides are available over the counter and by prescription. Be sure to read and follow all package instructions.


  • Suffocation –This includes suffocating the lice with mayonnaise or olive


  • Electronic devices – There are electronic combs available that detect and remove


  • Other agents, such as natural remedies, are


Check with your pharmacist or health care provider to determine which method is best and safe for your family.  NEVER use any flammable substance such as kerosene or gasoline.  Hair coloring such as bleach or dye is not an effective treatment.


  1. Should I treat all family members?
  2. All family members should be carefully examined for head lice and treated only if head lice are found.
  3. Who should be notified?
  4. The parents should notify any close contacts such as playmates or friends who have slept over as transmission occurs by head to head contact. Notices are not sent home by the school.
  5. Can my pets get head lice?
  6. No, headlice only live on humans.



  1. Do I need to get rid of the nits?
  2. Yes. Every successful lice removal program must include manual nit picking. Lice combs work well, as do fingernails. Getting rid of head lice requires time and patience. It can take 4 – 6 weeks to remove all viable nits. Nits found ½ inch from the scalp have probably hatched.
  3. How do I treat my house?
  4. The most important place to concentrate is on the student. However, clean all items that have been in contact with the head of the person within the past 48 hours. Wash bed linens. Wash or vacuum stuffed animals and you may store items in a sealed plastic bag for 14 days. Drying items at temperatures greater than 130 degrees will kill stray lice or nits. Vacuum furniture, carpeting and car.
  5. Q. Should I spray my house with insect spray?
  6. No, it is not recommended, as exposure to humans cannot be controlled and nits are unlikely to incubate and hatch at room temperature. Once hatched, head lice do not survive off the human head.
  7. Can my child get sick from head lice?
  8. Head lice are a nuisance; however, they are not known to spread any disease agents. The greatest danger is a secondary infection from scratching the head.
  9. Will a child with lice be sent home immediately?
  10. Not necessarily. If a child has live lice, the possibility of transmission to others has been present for at least a month. Sending children home deprives them of valuable educational time, however, the school nurse will determine if the student needs to go home.
  11. Will my child’s class be checked?

No.  Screening for nits is not an accurate way of predicting if children are or will be infested and screening for live lice has not been proven to have a significant effect on the incidence of head lice in school