Genesee County Health Department

Better Life Through Better Health

Head Lice

Each week area schools report the number of children with head lice to their local health department.  Although anyone can get lice regardless of age, income, race or ethnicity, most cases occur in children.  Parents and caregivers need to know what to look for.  And they need to know what to do when children have lice.

A head louse is a tiny brownish, wingless insect, which lives by feeding off the human scalp.  Head lice do not hop, jump, fly or swim.  They move about on a head by grasping onto a hair shaft with the lobster-like claws on the end of their appendages.  They live close to the scalp where the temperature is to their liking and their food (human blood) is readily available.  Lice are sensitive to heat and light.

Signs of an infestation may be intense itching and seeing the insect (which is about the size of a sesame seed) and/or their eggs, called nits.  Mature head lice are large enough to be seen by a person with normal vision.  Nits are about the size of a grain of sand and a whitish/opal color.  Nits are firmly attached to the hair shaft near the scalp with a glue-like substance.  Nits are not contagious and do not fall or come off of the hair shaft voluntarily.  They are often confused with dandruff, scalp tissue that is sloughing off, dried shampoo or hair care products.

Neither lice nor nits can survive when the temperature is far from the normal temperature of the scalp.  Nits survive longer than live lice do when off of the scalp; however, they need to have a meal soon after they emerge from the egg.  Like their larger relatives, when they come out of the egg case they feed only on human blood, not on the blood of animals; their only food is blood from the scalp.  Other parasites live on other parts of the body, and take bloody meals, but, generally speaking, the head louse lives only on the scalp of a warm human.  Unlike fleas, which are about the same size, lice do not live in carpets or vacuum cleaners.

For additional information, contact the Genesee County Health Department at (810) 257-3612.