Head lice are a much-dreaded infestation of parasites. They feed off of blood, and the head region is an ideal place for them to live because they can hide in the contours of hair.
The occurrence of head lice is so common that researchers estimate infestations cost nearly $1 billion every year in the United States. This takes into account money spent on commercial treatments, lost time at work and school, and products used to wash bedding and other household items.
Not only can lice be an expensive problem, but they pose grave discomfort and are persistent as well. Any person who comes into close contact with someone who already has lice is at risk. Infested clothing and personal belongings also pose danger.
The challenge of lice is not only in finding them, but also adequately treating them to prevent a recurrence.
Three Life Stages of Head Lice
Lice actually occur in three essential life stages. These are the nit, nymph and adult.
#1 Nits- Nits are lice eggs firmly attached to the hair shaft. They require approximately one week for hatching, and females place them 1/2-inch from the scalp for a ready food supply.
#2 Nymphs- Nymphs are baby lice freshly hatched from their eggs. They pass through a total of three stages before becoming fully matured. In order to survive, nymphs need a steady blood source, and are likely to remain in close proximity to the scalp until they develop their adult forms. Approximately eight or nine days after hatching, nymphs mature into adults.
#3 Adults- Adults are fully-matured lice who also feed on blood. Females are typically larger than males, and both sexes can survive up to 30 days on a person's head. However, if a louse falls off of a person, it will die within 48 hours. This is largely because head lice cannot hop or fly to another food source. They move by crawling, and researchers estimate they are able to speed through hair at a rate of nine inches per minute.
Adult females lay an average of six or seven eggs per day. This means that only one pregnant female is required to produce enough offspring for a significant infestation. Such can occur within a month, and scientists indicate that a child with a serious infestation has had lice for more than 30 days. Researchers believe children are most contagious while they have adult lice living on their heads.
Appearance of Lice
One of the single most difficult problems associated with head lice is actually seeing them. They are very small and remain well-hidden throughout their life. Not only do lice require a steady supply of food, but they also need warm temperatures in which to survive. Thus, the head is an ideal place for them to thrive.
- Nits are the easiest stage of lice to find. This is because the eggs do not move and instead remain attached to the hair with a glue-like substance. However, their appearance is often mistaken for hair spray droplets or dandruff. Nits are oval-shaped and tend to be white or yellow in color. They turn brown before they hatch and feel hard to the touch. Even after the lice hatch, the nits remain affixed to the hair shaft.
- Nymphs look like an adult head louse, but smaller. It is often challenging to find them without looking through a magnifying glass. Their minute size and tendency to stay hidden make them hard to find.
- Adult lice are approximately the size of a sesame seed, which is 1/10 to 1/8 of an inch long. They have six legs and are grayish-white or tan in color. Because of their indistinguishable color, adults are often difficult to discern. In persons with darker hair, lice often appear darker. The same is true of persons with lighter hair as well.
A sure way to detect lice is by looking for them. Although adult lice can move quickly away from prying fingers, eggs cannot. Researchers indicate that an infested child can have as many as several hundred nits. A magnifying glass and a strong light will help determine their presence. Hair should be separated into sections at the scalp and carefully examined. Once an infestation is determined, a safe treatment should immediately ensue.