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Stages of Head Lice

"Head lice spread easily and infestations often occur at all social and economic levels, especially among school children who are in close daily contact," reports Steve Tvedten in "The Best Control." Lice survive by biting and sucking blood, and the disease infects over 10 million children each year. The nits are notoriously hard to remove. In fact, the term "nit-picking" was invented to describe activities just as frustrating to complete. Tvedten says that "the punctures lice make while feeding and people make by scratching will transfer bacterial infections, which explains the statement 'feeling lousy.'"

Eggs or Nits
- Females lay their eggs close to the scalp and cement them to the base of the hair. Known as nits, the oval eggs and empty shells look like tiny white or tan dots and turn grayish or pearly white after death. "Live nits may be occasionally found anywhere on the hair shaft," reports Tvedten, "but normally they are found near the scalp and they are 'super-glued' on and do not flake off like dandruff." Eggs usually hatch within eight or nine days.
Nymphal Stages
- Each louse remains in the nymphal stages for about eight or nine days as well. Over the course of all three stages, nymphs look like adults excepting size, sexual organs and color. During the first stage, the nymph is straw colored and contains no central nervous system. You can see its stomach through the translucent skin, and it appears bright red after the nymph's first meal of blood, it then turns purplish-black. Nymphs feed twice daily and shed between stages.
Adults
- After the third nymphal stage, lice molt and become adults. The adult male lives for about 10 days, but the female can survive anywhere from nine to 22 days. Each female lays between six and 10 nits daily, and around 88 percent of these hatch. "They vary in color from dirty white to reddish-brown to rust to grayish black in color," reports Tvedten. Lice are about the size of sesame seeds and live in warm moist habitats. Some report a lice strain that travels by jumping, but most strains spread by crawling.
Spread and Treatment
- The easiest way to remove nits is to cut them out. However, you can also try soaking the hair in a mixture of baby oil and vinegar, or in a diluted solution of any lice removal product. You can find nit and lice removal kits at your local pharmacy. Lice spread through direct contact, which usually limits transmission to those who share brushes, combs, knit hats, etc. If you suspect an infestation of lice, make sure to get everyone's brushes and check them to prevent re-infestation. Be sure to remove every single nit and louse to prevent re-infestation. Use a magnifying glass and bright light on hair strands, brushes and hats to do so.

Insects & Science