Lice are every parent’s worst nightmare. Given the chance, they will happily infect the heads of every family member, wreaking havoc on your scalps until the problem is solved. While most people have general knowledge of head lice and how to get rid of them, how much do you really know about these little bugs? This guide will give you more insight into what head lice are, how they reproduce, and how to prevent them.
What are head lice?
Head lice are a species of obligate ectoparasite, meaning that they spend their entire life cycle on their host. They are clear in color until they eat, and then their translucent bodies show the blood they’ve eaten — turning them brown/red.
Lice are small, nearly microscopic insects, and unlike fleas, they cannot jump. In fact, head lice are incapable of walking properly. In order for them to move, direct contact has to be made. From there, they can get caught on hair follicles and begin a new life on another host. Once they’ve found real estate on a new head, they can begin the reproduction process.
Some studies report that girls are two to four times more likely to contract lice than boys.
Interestingly, the species of louse that infects human heads can only live on humans, while other species thrive on birds, chimps, and other mammals. The lice that infect other parts of the body, including pubic lice (or crabs), are a completely different species. While body lice do exist, they are a separate entity from head lice, and they rarely interbreed.
Unlike body lice, head lice are a purely cosmetic issue, and they are not known to carry any diseases. However, that doesn’t make them any less troublesome and annoying. Luckily, a solid understanding of their epidemiology and reproduction cycle can help you eliminate and prevent head lice in the long run.
Lice infection rates around the world
Research by the CDC has shown that high levels of lice infestation were found among people who have straighter hair. This aligns with the morphology of the louse — their legs are made for grasping straight hair follicles, and straight hair is easier to move through. Countries with high rates of straight hair (USA, UK, Denmark, France, Australia, Sweden, etc.) also had a higher number of lice cases.
Also as a result of their morphology, lice are less likely to survive on children and adults of African descent. Their coiled and textured hair does not provide a welcoming environment for head lice. However, this does not mean they are immune to lice, just less at-risk than children with straight hair.
Girls have a higher rate of lice infestation than boys. In fact, some studies report that girls are two to four times more likely to contract lice than boys. This is likely due to the fact that girls tend to have longer hair, making it easier for lice to latch on. It also typically takes longer for girls to get rid of lice, since they have more hair to treat. This allows the lice more time to spread to family and friends.
How lice reproduce
The louse reproduction cycle has multiple stages, but these stages can occur in quick succession. Lice have three primary life stages: egg, nymph, and adult. Because of their rapid reproduction, getting rid of lice can be a tiresome process that involves eliminating all living adults, adolescent nymphs, and active eggs.
Many people find that while they are able to pick adult lice out of their hair, they might miss eggs and nymphs entirely. For that reason, treatment must involve a poison or oil of some kind. However, for every moment that the lice are alive, their sole focus is surviving and reproducing. The louse reproduction cycle goes as follows:
- Eggs – Adult female lice lay eggs, or nits, which they attach to the hair follicle. While not invisible to the naked eye, these can easily be mistaken for dandruff or skin particles. If you are not looking closely, they might be missed entirely. It takes about a week for the eggs to hatch, and the emerging nymphs travel to the scalp to feed.
- Nymphs – The nymph stage has multiple evolutions, which are benchmarked by molts. It takes a louse nymph three molts to become an adult. These three molts can occur over the course of a week. Once the nymph has reached adulthood, they can begin breeding and producing eggs.
- Adults – The final stage of the louse’s life. However, it is also the longest. According to the Mayo Clinic, an adult louse can live for up to 30 days on the scalp of its host. Every day, the adult louse does nothing but eat and reproduce. A female louse can lay up to 8 eggs per day, which can result in over 200 offspring by the end of her life cycle. Over the course of this month-long life, her offspring can reach adulthood and begin laying eggs of their own, reproducing exponentially until they are either picked off or killed.
Because lice have few needs, they can survive intense conditions and continue breeding. Washing your hair might dislodge a few adult lice, but it will not destroy the infestation. In order to get rid of lice entirely, a treatment plan is necessary.
How to recognize lice
In order to begin treating someone for lice, their case has to be recognized. Some people go weeks without realizing what’s living on their head, and children might not have the knowledge or ability to recognize that they have lice. By the time you realize you or your child has lice, the reproduction cycle might already be well on its way. Some parents are able to intercept before the process truly begins, but advanced cases of head lice can be difficult to treat.
For that reason, you must be able to recognize lice in their early stages. While nits are extremely small, they are visible to the naked eye. They are usually found near the scalp, and might be mistaken for skin particles or the gloss of hair strands. Adult lice are easier to spot, and can be picked off the head using your fingers or a comb. Lice combs are extremely fine-toothed, and can catch lice in-between the tines. However, people with curly or coiled hair might have a hard time using these combs.
It’s important to remember that picking away the adult lice will not eliminate the problem. While you might not be able to see any more lice, that doesn’t mean they aren’t there. They can live on the back of your head or deep in your hair. It’s extremely difficult to be thorough, especially when you or your child has long hair. Picking off the adults also leaves the eggs and any escaping nymphs, which can hatch and mature into adults.
If you or your child has contracted lice, action must be taken quickly to avoid a household infestation.
If someone in your household has an active case of lice, everyone in the home must be checked.
How to get rid of lice
The treatment plan for lice doesn’t just involve eliminating them from your head. It also involves getting rid of nits, washing pillowcases and clothes, and developing a prevention plan.
If someone in your household has an active case of lice, everyone in the home must be checked. Otherwise, you might re-infect each other after the original carrier is treated. All pillowcases, hats, scarves, and hooded coats must be washed and dried with hot water or quarantined for 24 hours or more. If you do not have a dryer, a hot-water cycle should be sufficient. It’s important to use high temperatures, as lice and their eggs can survive cold/warm water.
Once everyone’s bedding and clothing is washed, it’s time to move on to the head. Everyone with active cases of lice should receive their treatments at the same time, and daily head-checks should be performed.
Many products exist to help people get rid of lice. These might include shampoos, conditioners, and mousse. Some of these products contain poisons that harm the lice, but are safe for humans in small amounts. Generally we recommend non-toxic treatments. Combs and hair oils can also be used to loosen the lice and remove them manually. With lice poisons, thorough washing, and regular combings, many people are able to dislodge adult lice and kill the nits before they hatch.
It’s important that those using lice treatments follow the instructions they are given by the doctor, pharmacist, or product label. Using too much can result in illness or other complications, while using too little can cause the product to fail. Even one or two surviving lice can go on to repopulate your head with nits and nymphs.
While some natural remedies exist for getting rid of lice, they might not be entirely effective. According to Medline Plus, there exists no factual scientific evidence that remedies like olive oil or mayonnaise are viable treatments.
Once you begin spotting dead or dying lice, you can begin combing out your hair to remove them. Continue your treatment for as long as your doctor or pharmacist recommends. Just because you cannot see any adult lice doesn’t mean there aren’t eggs or living lice on your scalp. Continue checking you and your child’s scalp for 2-3 weeks after the treatment is finished, just to make sure it was successful.
If you spot any surviving lice, talk to your doctor or pharmacist about secondary measures. If your original treatment plan does not work, you might need to try another one in order to see permanent results.
How to prevent lice
If you’ve already suffered a case of lice, you might already know how stressful and frustrating it can be. You might want to spare you child the same experience, or prevent another one from occurring. Parents can take measures to prevent lice by remaining vigilant. Even if you tell your child not to share hats or touch heads with their friends, children rarely follow these instructions. Kids tend to be more interactive with each other, which makes transmission between them more common.
However, measures to prevent lice can be taken in case your child’s school or daycare has recently suffered a breakout. Assuming your child hasn’t already been infected with head lice, here are some preventative steps you should take:
- Talk to your child about lice. Simply telling them not to share hats, hair ties, and combs with their friends is not enough. If the child does not understand why they cannot do these things, they’re less likely to follow your instructions. Inform them about lice and how they spread, and they will naturally do what they can to avoid them.
- Ask your child to avoid head-to-head contact for a little while. This includes braiding hair, hugs, and sitting close together. While your child shouldn’t be afraid to interact with their peers, you can ask them to avoid it for a little while until their classmates have been checked and treated.
- Use hairspray. While this is not foolproof, it can offer some protection if you’ve heard rumors about lice at your child’s school. Hair spray makes it difficult for lice to latch onto hair follicles, so it can be used to protect your child’s hair from lice.
- Perform regular head-checks. It’s better to be safe than sorry. No matter what measures you take to avoid head lice, you can never be too sure. Your child might get lice from being on the bus, playing with friends, or using headphones at a class computer. Every time you put your child in the bath, ask to check their head for lice. Regular head-checks give you the chance to spot lice early, avoiding a total infestation.
While you cannot protect your child at all times, you can give them the skills they need to avoid lice themselves. Adults can prevent contracting lice by following these steps as well. Perform head-checks on yourself in the mirror, and wash your hair often and thoroughly.
(Not so) fun facts about lice
- Lice can also be found on eyelashes and eyebrows.
- They are commonly found behind the ears and at the nape of the neck, since these areas are typically warmer.
- Anyone can get lice, regardless of cleanliness or socioeconomic background.
- Lice die in 1-2 days if they are left without food (human blood).
- Because head lice only infect humans, you cannot give lice to your pet, nor can you catch lice from them. However, dogs and cats do have their own species of lice, which can cause problems of their own.
- Lice have existed for most of human history. Mummies with dried-up lice in their hair have even been discovered.
- Female lice stick their eggs to the hair follicles using their glue-like saliva. Gross.