How and When Do Head Lice Feed
Head lice feed on the blood of their host by piercing the skin with their mouthparts. They then add saliva to the wound to keep it from clotting. The blood is then swallowed through two tiny blood vessels in their head. These blood vessels are partly transparent, and you can see a thin blood thread running out of their mouth.
Lice are usually very tiny, about the size of a pinhead. They are usually gray or tan in color and are found on the scalp. Once hatched, head lice live for 35 days and feed on the blood of a human host several times a day. Adult head lice can live for three to four weeks if they are untreated. Their life cycle continues once they have fed and they will lay their eggs near the scalp. The lice then go through one molt and begin their second and third cycles.
Once an infestation is confirmed, it is possible to use a number of home treatments. The first step is to inspect the head. If you find a live louse, you should use a magnifying glass or fine-tooth comb to locate it. Another step is to inspect for nits. If you see them attached to the hair shafts within 1/4 inch of the base, there is a strong possibility of head lice infestation. If you notice nits outside of this area, these are almost certainly hatched.
Once you have head lice, you should do your best to eradicate them immediately. The most common way to eradicate the infection is to treat the source of the infestation. Infections often spread from person to person and clothing to clothing. The infection can also be spread via bedding, towels, and hairbrushes.