Pediculus humanus capitis, the louse that infects humans, lives and breeds on the scalp. The head louse is a parasite, feeding on its host's blood. The louse does not infect other areas of the body, and remains on the scalp during its entire life span of four weeks. A female louse lays 50-150 nits (eggs) that will hatch and become nymphs. Three moltings later, as louse develops into a nymph 2 and nymph 3, the louse finally becomes an adult male or female.

Adult head lice reproduce very frequently, with the females laying three to four eggs per day on average. A lice generation typically lasts for one month. The female then will attach her eggs at the base of the hair follicle of the host. Any part of the host's scalp can be colonized, but adult lice tend to favor the nape of the neck as well as the general area of the rear of the ears and tend to place their eggs there most frequently.

A common symptom indicating infestation is the presence of pruritus on the head, which gets worse after three or four weeks. Bites are relatively mild and may not even be visible between hairs. In individuals with long hair, you can see bites when the hair is pushed aside. Sometimes, although rarely, the itching and scratching cycle can cause secondary infections such as impetigo and pyoderma. Rare symptoms include swelling of the local lymph nodes or fever. Head lice have not been found to carry any pathogenic microorganisms.

How to get rid of lice?Well that is a tough question because there is practically no product in the market, which kills 100% of the eggs after a single treatment.Various methods used include chemical treatment,hot air, combs, shaving the head,dimeticone etc.It is not recommended to use kerosene (alone or in combination with oil and vinegar), hair bleaches and dyes, antibiotics or ivermectin for treatment and garlic and Vitamin B for prevention.

Despite countless efforts to eliminate head lice, the pests have a strong reputation for resistance. As with other "superbugs" in today's medical and scientific age, head lice are becoming increasingly aggressive against treatments commonly used today. It is believed that up to 80% of lice are capable of resisting unprescribed methods, including chemicals such as permathrin and phenothrin.

An infection of head lice is notoriously difficult to treat, so prevention needs to be the first priority. Scientists have found that many lice have developed a resistance to most lotions currently used, through natural selection. As a result, there is now a scramble to develop new treatments that will effectively eliminate lice. In the meantime, teachers, parents, and children are left to their own devices.