Lice Life: The Brief Wondrous Life of a Head Louse

Fun Lice Facts From Nit-hood to Adulthood

Pediculus humanus capitis, more commonly known as head lice: the tale as old as time reminding us not to share hats and brushes and wash our hair frequently. Though most of what we know about lice is merely a myth, most people know nothing about the lifespan of these tiny little creatures. Though often cut short, the lifespan of a louse goes through three very distinct stages. These stages are important to understand for anyone looking to get rid of a lice infestation or prevent getting lice in the first place. That’s why we at the Hair Whisperers - Southern California’s most trusted in-home lice removing professionals - have created a quick outline of the lifespan of these fascinating parasites.

Stage 1: Nits as a Humble Beginning


Lice, because they are insects, begin their lives in eggs laid by a female louse. These eggs, known as nits, are teeny tiny (0.8mm by 0.3 mm) white or yellow specks that can be found close to the human scalp. Female lice lay eggs close to the scalp for warmth and so the eggs have a place to cement themselves for development.

A female louse will lay about a half dozen eggs a day and nearly 150 eggs in her short lifetime. Nits are often confused for dandruff or hair spray droplets, making them difficult to detect without careful inspection. It’s also hard to spot nits at the beginning of an infestation until the infestation begins spreading exponentially as more lice reach adulthood and lay eggs. This stage of having lice is not typically itchy because very few louse bites have occurred on the scalp at this point and there are not many fully-grown lice on the scalp yet.

After approximately a week, a nit will hatch and then call the scalp it was hatched on home and enter its nymph stage.

Stage 2: Childhood as a Nymph

 lice nymph

After a nymph hatches, the nit often become more visible as it can finally detach from the hair.  Freshly-hatched nymphs are very difficult to spot because they are very tiny - about the size a pinhead - and then begins a three-step molting process:

  • Molt #1: The tiny nymph has six legs - three on each size of its body, all approximately equal in size. The nymph is almost transparent and its body disproportionately large compared to its tiny head and legs.
  • Molt #2: The body elongates and narrows slightly as the front legs become more prominent and defined, preparing the nymph for adult locomotion. Their claws begin to develop.
  • Molt #3: The body of the louse grow tremendously and a visible difference between a male louse and its larger female counterpart develops. As the hind area of the body expands, the legs and claws continue to strengthen and develop.

The three molts occur over the span of about a week, meaning that after about two weeks into its lifespan, the louse reaches adulthood. In this stage, the louse begins biting the scalp to feed off of blood for its nutrients, making lice parasites off the human scalp.

Stage 3: Adulthood as a Louse


By the time a louse reaches adulthood, it is typically the size of a sesame seed (often not surpassing 2mm in length) and is greyish-brown in color, and may be darker in individuals with dark hair. The male and female lice now begin to mate and reproduce, laying nits one two days after mating.

In the meantime, the lice feast on human blood about four times a day for the next thirty days. In those thirty days, a female louse will lay eggs ten to thirteen separate times, allowing the cycle to start over again. Because of this, it’s easy to understand why lice reproduce quickly and become an infestation without quick, proper treatment.

Although an adult louse survives about a month while on the scalp, it cannot survive more than 24 hours when not on the scalp because it cannot find the nutrients to survive. Additionally, a louse is unable to lay nits if it is not on the scalp because the scalp provides a sturdy place for eggs to stay and the warmth they need to develop and hatch. This is why the myth of sharing hats and scarves is less of an issue than many lead on to be; the primary way in which lice spread is from head to head contact where the lice can immediately find another source of nutrients and shelter.

What do I do next if I find a louse in any of these stages?

Woman Wearing White Long-sleeved Shirt

The key to preventing a major lice infestation is early detection. Taking an extra second to examine your child’s scalp when combing their hair following a bath or shower is a great way to detect nits of lice early in this lifespan and before the issue becomes out of hand.

If you find your head lice infestation has become a little more serious, it’s best to skip lice shampoos and over the counter remedies, because they’re not the best course of treatment. Missing just a single louse can lead to a continuous cycle nits being laid and the rebirth of an infestation.

That’s why lice removal professionals recommend combing and nit picking (see where it comes from, now?) methods for removal. A professional lice remover has special tools and a keen eye for nits and lice and can often help you get rid of lice in a single treatment. Though sometimes a little more expensive that shampoos and other treatments, hiring a professional lice remover is worth the peace of mind that comes from the end of an infestation.


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