- WHAT ARE LICE?
Lice are small, wingless, grayish-white insects with flattened, elongate
bodies and somewhat oval heads. They are about 1/16 to 1/8 inch long.
- ARE THERE DIFFERENT KINDS OF HUMAN LICE?
There are several species or kinds of lice that feed on people. One
species feeds specifically on the head and is called the head louse.
- CAN HEAD LICE SURVIVE ON PETS?
No, head lice are obligate parasites of humans, i.e., they must feed
on humans in order to survive.
- HOW LONG DO HEAD LICE LIVE?
Lice may live for several weeks on a person, but they rarely live more
than 48 hours when removed from a person's body.
- CAN HEAD LICE HOP OR JUMP?
No, head lice cannot hop, jump or fly. Their legs are adapted for grasping
a person's hair.
- DO HEAD LICE SPREAD DISEASES?
No, head lice are not known to transmit any disease agents. However,
secondary infections may result if the skin is broken by repeated scratching.
- WHAT ARE "NITS"?
Nits are louse eggs. They are small (about 1/32
inch), white to cream color, and oval in shape with a distinct cap.
Nits are often the first sign of a head lice infestation.
- WHERE ARE NITS FOUND?
Head lice glue their eggs to the base of the hair shaft, frequently
behind the ears or on the nape of the neck.
- HOW MANY EGGS DOES A FEMALE HEAD LOUSE LAY?
A female head louse produces about four eggs per day and a total of
about 88 eggs during her lifetime.
- HOW DOES SOMEONE GET HEAD LICE?
Lice are transmitted by close personal contact with an infested person
or by sharing their articles of clothing and personal items such as
hats, headbands, scarfs or caps, combs and brushes.
- HOW MANY HEAD LICE ARE USUALLY FOUND ON AN INFESTED PERSON?
Typically, 10-15 head lice are found. The number of lice often depends
on personal hygiene, for example, how often the person bathes, shampoos
or changes and washes his/her clothing.
- WHO IS MOST LIKELY TO GET HEAD LICE?
Head lice have been found on people of all socio-economic levels. Children,
particularly those of elementary school age, are most likely to get
head lice because of their close contact and social interactions with
each other (e.g., sharing hats, combs and brushes).
- IS IT TRUE THAT AFRICAN-AMERICANS DO NOT GET HEAD LICE?
No. Although factors such as hair texture may make African-Americans
less likely than Caucasians to get head lice, they are not immune to
- HOW CAN YOU TELL IF SOMEONE HAS HEAD LICE?
Lice cause intense itching of the scalp. Parents and teachers should
watch for children who scratch their heads constantly or excessively.
In such cases, check the scalp for nits or lice. If you're not sure
what to look for, ask for help from someone who can positively identify
the eggs or the insects.
- HOW CAN I CHECK MYSELF OR MY CHILD FOR HEAD LICE?
One simple way to check for lice is to have the person hold their head
over a light-colored towel. Then, brush the hair and scalp vigorously
towards the towel. Dislodged lice will be found on the towel. Because
infested people usually have few lice, you can easily miss finding them.
It is important that you carefully and thoroughly inspect the person's
head, particularly the back of their neck and around their ears. Remember:
dandruff, oil droplets in the hair and even flakes of hair spray can
be confused with nits. Use a magnifying glass to help check for nits.
When in doubt, consult a physician or your local health office for assistance.
- WHAT SHOULD BE DONE IF YOU SUSPECT SOMEONE IS INFESTED?
They should seek help from their physician, county health department
or school nurse. The entire family needs to be examined and treated,
if necessary. In the case of school-age children, notify the principal
immediately. Other children in the class must be checked by a doctor,
school nurse or other health official. Letters can be sent home to notify
each family of the problem and the possible need for them to take measures
to prevent further spread of lice to other family members. The letters
should help solve the problem and should not be used to single out any
child as the cause of the problem.
- WILL SOAP AND WATER KILL LICE?
Shampooing with regular non-medicated shampoos can help prevent an infestation,
but it will not eliminate an active one. Washable clothing, hats, head
bands, bed linen, towels and other personal items (such as brushes and
combs) should be washed in hot (120oF or higher) soapy water,
then dried in a clothes drier for at least 20-30 minutes. Woolen or
other non-washable clothing can be dry-cleaned, but this additional
expense can be avoided by simply isolating the articles for 1-2 days.
Items such as stuffed toys do not need special treatment; however, if
it make you feel more at ease, you can put them in the clothes dryer
for 45-60 minutes
- WHAT MEDICATIONS ARE EFFECTIVE AGAINST LICE?
Several "over-the-counter" products (pediculicides) are available to
you at most drugstores. These include RID®, A200® and R&C
Shampoo®, and Nix®. Ovide®, a shampoo
that contains the insecticide "malathion" is available by prescription.
- DO THESE MEDICATIONS KILL THE EGGS?
Over-the-counter products work well against the nymphs and adults, but
most will not kill the eggs. Read the product labels carefully. Consult
your family doctor about what is best for you to use.
- HOW IMPORTANT IS IT TO KILL THE EGGS?
Mechanical removal of louse eggs helps reduce the number of lice that
might hatch on the scalp. Even if you use Nix, the egg "shells" may
remain attached to the hairs, giving the impression of an active infestation.
Since children who are declared "nit-free" can return to class sooner,
removing nits has a positive impact on their morale and lessens disruption
to their school activities. Special combs are provided with the pediculicides
and should be used according to the product instructions. Nits are more
easily removed after shampooing the hair, when it is still damp.
- DO VINEGAR RINSES HELP REMOVE LICE EGGS?
No, vinegar will not dissolve the cement-like substance that the female
louse uses to attach her eggs to the hair shaft. A nit comb is the only
real reliable method for removing the eggs. Although trimming the hair
is not necessary, it does makes it easier to remove all of the nits..
- DO I NEED TO SPRAY MY HOME WITH AN INSECTICIDE IF SOMEONE IN MY
FAMILY HAS HEAD LICE?
No, lice cannot survive for more than about 24-36 hours when removed
from a person and they do not live in cracks or crevices like cockroaches
or other household pests. Spraying furniture, carpets and bedding with
an insecticide serves no real purpose other than providing some margin
of psychological comfort. Although such sprays kill an occasional stray
louse, family members who are already being treated with insecticidal
shampoos would be exposed unnecessarily to additional pesticides. If
anything, vacuuming carpets and furniture will remove stray lice.
- WHAT ELSE SHOULD BE DONE IN THE CLASSROOM TO GET RID OF LICE?
The need for delousing measures in a school depend largely on the age
of the students and the layout of the classroom. As in the home, vacuuming
carpeting and/or sleeping mats can help. Mats with vinyl or other non-fabric
coverings can be cleaned with hot, soapy water. Clothing or personal
items (such as those described in question 17) that students have left
in a closet, storage area or desk should be removed and deloused. Application
of insecticides in the classroom is not necessary and is strongly discouraged.
For information on the various lice that infest humans, see Insect Note
ent/RSC-7, Biology and Control of Human Lice
Image of louse: Department of Entomology, University of Nebraska