Fact sheet - Health conditions directory
Head lice (Pediculus capitis) are small, wingless, egg laying insects found on the human head. They grow to about 3.5mm (the size of a sesame seed or pin head). Head lice live on the hair and feed by sucking blood from the scalp. They are pale grey in colour before feeding and reddish brown after feeding.
Live eggs (sometimes called nits) are glued to the hair shaft within a distance of 1.5 cm from the scalp. They hatch in 7-10 days as young lice (nymphs). It takes up to ten days for the nymphs to become mature lice and begin laying eggs. Adults are larger than nymphs and a mature female lays up to eight eggs per day.