What are lice?
Lice are tiny insects that live on humans and feed on blood. When a large number of lice live and multiply
on a person, it is called an infestation.
Lice die if they are away from a human's head or body for more than 2 days. Lice are 1-3 mm long
(about the size of a sesame seed) and cling to the hair shaft. During the life cycle of lice, the female
louse lays eggs, called nits that attach to the hair shaft close to the scalp or body. These nits, which
resemble dandruff, will attach with a gluelike, water-insoluble substance that makes them difficult to
remove. After 6-10 days, the nits hatch as nymphs and become adults in 10 days. Adult lice live about 30
days on their human hosts.
Head Lice are usually found in hair, most often on the back of the neck and behind the ears. Head lice
are common in preschool and elementary school-age children. Adults can get them too, especially adults who
live with children.
How Can I Tell if My Child Has Lice?
Though very small, lice can be seen by the naked eye. What you might see by thoroughly examining your child's head:
Lice eggs (called nits), which look like tiny yellow, tan, or brown dots before they hatch. After
hatching, the remaining shell looks white or clear. Lice lay nits on hair shafts close to the skin's surface,
where the temperature is perfect for keeping warm until they hatch. Nits look sort of like dandruff, only they
can't be removed by brushing or shaking them off. Unless the infestation is heavy, it's more common to see nits
in a child's hair than it is to see live lice crawling on the scalp. Lice eggs hatch within 1 to 2 weeks after
they are laid.
Adult lice and nymphs (baby lice). The adult louse is no bigger than a sesame seed and is brownish tan
(although lice may look darker on people with dark hair). Nymphs are smaller and become adult lice about 7 days
after they hatch. Most lice feed on blood about every 4 to 6 hours, but they can survive up to 3 days off the scalp.
Scratching. With lice bites come itching and scratching. However, the itching may not always start right
away - that depends on how sensitive your child's skin is to the lice. It can sometimes take weeks for kids with
lice to start scratching. They may complain, though, of things moving around on or tickling their heads.
Small, red bumps or sores from scratching. For some the irritation is mild; for others, a more bothersome
rash with crusting and oozing may develop. Excessive scratching can also lead to a bacterial infection (the skin
would become red and tender around the bite area).
What are lice?