Adult: The adult body louse is about the size of a sesame seed, has 6 legs, and is tan to greyish-white. Females lay eggs. To live, lice must feed on blood. If a louse falls off of a person, it dies within about 5–7 days at room temperature.
Adults: The adult louse is about the size of a sesame seed, has 6 legs (each with claws), and is tan to grayish-white. In persons with dark hair, the adult louse will appear darker. Females are usually larger than males and can lay up to 8 nits per day. Adult lice can live up to 30 days on a person's body.
Head lice are oblong and flat insects, whose bodies are divided into three parts: Head, thorax and abdomen.
For example, Steinbrecht (1994) found tuft organs in the body lice, concluding after an exhaustive study that these structures represent thermo/hygroreceptors. Similarly, we identified tuft organs in the F2 and F3 of the head lice antennae.
Nymphs shed their skin (molt) three times and become adults about 9-12 days after hatching. Adult body lice are tan to grayish-white in color, have six legs, and are about the size of a sesame seed.
Sometimes body lice are be seen on the body when they feed. Body lice eggs usually are seen in the seams of clothing or on bedding. Occasionally eggs are attached to body hair. Lice found on the head and scalp are not body lice; they are head lice.
You can get body lice if you come in direct contact with someone who has lice. You can also get lice from infected clothing, towels, or bedding. Body lice are bigger than other types of lice. You are more likely to get body lice if you do not bathe and wash your clothes often or live in close (overcrowded) conditions.
An adult louse will feed on human blood 5 to 6 times per day to survive. Each time they use small, sharp teeth at the end of a tube that acts as its mouth. The louse will use this tube as a suction cup, cling to the skin of its host, and insert the sharp teeth to penetrate the skin and feed on blood.
After mating, a female louse can store the sperm in a container in her body, so she does not need to mate again to continue producing eggs.
Adult lice can live up to 30 days on a person's head. To live, adult lice need to feed on blood several times daily. Without blood meals, the louse will die within 1 to 2 days off the host. Life cycle image and information courtesy of DPDx.
Head lice are not known to reproduce asexually (or through parthenogenesis), although the genetic reproduction of head lice isn't exactly what you'd expect from the classic Mendelian model.
To survive, adult head lice must feed on blood. An adult head louse can live about 30 days on a person's head but will die within one or two days if it falls off a person. Adult female head lice are usually larger than males and can lay about six eggs each day.
Head lice do not have wings or jumping legs, so they cannot fly or jump from head to head. They can only crawl. People catch head lice from direct head-to-head contact with another person who has head lice.
There is no way to look at a nit with the naked eye and determine if it is dead or alive. And although some people claim it does, popping them does not prove that one way or the other either. They are just too small. The only proof is when they don't hatch 7-10 days later.
In addition, fieldwork has shown that, in populations living in extreme poverty, the proliferation of head lice led to the emergence of lice able to adapt to clothes and turn into body lice. These body lice were then able to cause epidemics of body lice and bacterial epidemics.
You may never know where your case of lice came from, but it started when either a pregnant louse or two live bugs made their way to your human head through head-to-head contact with another human head hosting an active case. If you just have eggs, then there was at one time one pregnant louse on your head.
The adult forms of the males and females — which look slightly different from one another — begin to mate and reproduce immediately. Females will lay their first batch of eggs around 2 days after mating. Females can keep laying eggs for the next 16 days — up to 8 per day.
Some studies suggest that girls get head lice more often than boys, probably due to more frequent head-to-head contact. In the United States, infestation with head lice is much less common among African-Americans than among persons of other races.
Head lice feed on blood from the scalp. The female louse lays eggs (nits) that stick to hair shafts. Head lice are tiny insects that feed on blood from the human scalp.
Although sometimes more tedious than chemical methods, mechanical lice treatment methods are far more effective at destroying lice for good. Lice may develop resistances to certain chemicals; however, they will never be able to resist being squished, zapped, smothered, or manually removed by the human hand.
Head lice have no wings and do not fly or jump, but they can crawl or run through hair quickly. Most commonly, head lice are spread by direct head-to-head contact with an infested person.
About head lice and nits
Brown-black nits are eggs that haven't hatched into lice yet. White nits are eggs that have already hatched.
Washing, soaking, or drying items at a temperature greater than 130°F can kill both head lice and nits. Dry cleaning also kills head lice and nits. Only items that have been in contact with the head of the infested person in the 48 hours before treatment should be considered for cleaning.
Not everyone feels lice moving around on their scalp, but some people do. Dr. Garcia says that most of her patients say they “don't feel anything,” but others may get a creepy, tickling sensation as lice move around their head.
Using your finger to check for and extract nits (eggs, each of which houses a baby louse) is an integral part of a lice check and can be helpful when treating an infestation. You can actually feel the nits stuck to the hair shaft; each one will feel like a bump on the hair.