What Are Lice

What Are Lice

Lice are parasites that feed on human blood and live on the hair and scalp, body, or pubic area. The types of lice found in these areas are all different.

Infestations of lice – any type – are caused in most instances by humans coming into close contact with each other allowing the lice to crawl onto the next victim (lice cannot hop or fly.)

For once, we cannot blame our beloved pets for spreading these pests because transmission of lice between animals and humans just does not happen.

Let’s look at each type of lice individually;

Head Lice – Pediculus Humanus Capitis

Head lice are parasites that are found on the scalp of humans. They can also be found in eyelashes and eyebrows – although this is relatively uncommon. They need to feed on human blood numerous times a day to survive, and for this reason, they tend to make their home close to the scalp.

The adult female will lay eggs (known as nits) at the bottom of the strand of hair (approx. six each day) – close to the scalp. The tiny, oval-shaped eggs are attached very firmly to the hairs shaft and are not easily seen by the human eye. Their size has been likened to that of a knot in a piece of thread. In color, they are often yellow or white, but it is not unknown for them to blend in with the victim’s hair color. Quite often, they can be mistaken for scabs or dandruff.

Not all the eggs will hatch – those laid too far from the scalp, i.e., more than 0.25 of an inch, are unlikely to do so. It will take up to 9 days for hatching to begin. The nymphs are just smaller versions of their parents. It is a further 9-12 days before the nymphs mature into adult head lice.

An adult head louse is roughly a sesame seed and can range in color from tan to a “dirty” white. It has six legs and needs regular meals of human blood to survive. On average, the ahead louse’s life expectancy is around 30 days, provided it remains on the victim’s head. Should it fall off, it can only survive for a couple of days at most.

Head lice are only spread by direct head-to-head contact with someone who is already infested because lice do not hop or fly. They have to crawl from one head to another. Schools can often have big head lice problems as they are passed from one child to another when heads are close together during play and activities. There has always been a common belief that they can also be spread by sharing combs, brushes, hats, etc. this is, in fact, an infrequent occurrence.

Getting head lice is no reflection of personal or household cleanliness – anyone can become infected!

Body Lice – Pediculus Humanus Corporis

This parasitic insect lives in the clothes and bed linen of those infested. The female will usually lay her eggs close to the seams of the person’s clothing. Infestations of body lice can spread rapidly, particularly in situations where people live close and where the hygiene standards are not particularly good. The homeless, refugees and anyone who does not have regular access to washing facilities, clean clothing, and bedding tend to suffer most from infestations of these blood-sucking pests.

Body lice feed on human blood but will only crawl onto the skin when it is meal time.

Body lice eggs – also known as nits, are usually found in or very close to the seams of the infested individual’s clothing and are usually more prevalent at the armpits and waist. It is also not uncommon for body nits to be attached to body hair. The eggs are oval in shape and white or yellow in color. It will take around 7 to 14 days for the eggs to hatch.

Once the miniature body louse – the nymph – emerges from the egg, it will take a further 9 to 12 days with regular meals of human blood before it becomes a fully grown adult body louse.

Once fully grown, the adult body louse is roughly the same size as a sesame seed, with 6 legs, and is usually tan or “dirty” white in color. Survival depends on having access to regular blood meals; therefore, should a body louse fall from the host, it will only survive for a limited time at room temperature – around 7 days maximum.

Pubic Lice – Pthirus Pubis

These parasites are also commonly referred to a “crabs” and are found mainly in the genitals or pubic area of the victim.

The female will lay her eggs – also called nits – on the hair shaft and are firmly attached with a cement-like substance. As with other types of lice nits, they tend to be white or yellow in color. The nymphs will hatch within 6 to 10 days.

The pubic lice nymphs are miniature replicas of the adults and need around 14 to 21 days to grow into sexually mature adults.

When inspected under a microscope, the adult louse very much resembles a crab. The front two of their six legs look like the pincer claws associated with crabs hence the common name for public lice – “crabs.” They also need regular human blood meals and will only live for a couple of days maximum if they fall from their host. In color, they are the same as the other two types of lice – tan or “dirty” white.

As I stated earlier, these lice are found in the genital or pubic area of humans. They can, on occasion, be found attached to other body parts where course body hair is found, such as the armpits, legs, beard, etc.

The spread of pubic lice is most commonly due to sexual contact between adults. However, it is not unknown for them to be spread from contact with clothing, bedding, or even towels used by the original victim. NOTE: They cannot be spread from sitting on a toilet seat!!!