Lice are parasites members of the order Phthiraptera, that live off of blood and are the most known parasites of humans, living in their hair, really close to the scalp. They can also easily infest birds and other mammals, and can be vectors of diseases, such as typhus. Out of almost 5,000 identified species, 4,000 of them affect mostly birds, and 800 usually infest mammals. They can be found on every continent, and in any type of habitat, as lice have also been found in the arctic, having penguins as hosts. They feed a few times a day, but they can also live 1-2 days without feeding, which makes them quite resistant and allows them to infest a new host. They are extremely contagious and you can get catch lice if you get close enough to someone infested, or by using the same towel, hair brush or clothes as someone infested with lice. They usually spend their whole life on a single host, cementing their eggs to hair follicles or feathers and then feeding on their host, generation after generation.
Description and diversity
Humans are affected by three kinds of lice: head, body, and pubic ones. However, they can also be divided into two categories, based on what they eat: sucking lice and chewing ones. The two types look similar, having flattened bodies and lacking wings, with the chewing ones being slightly larger. They both lack ocelli, and only have compound eyes, but the main characteristic of their head is their mouthpart. For the sucking lice, the mouthpart is retractable into the head and is highly adapted for piercing the skin and sucking blood. They also have a single large claw, positioned at the tip of each leg, which helps them remain attached to their host and the hairs they use to crawl on and move. When it comes to the mouthpart of the chewing lice, it is adapted for chewing, rather than sucking. Their legs are short, with one or two claws at their tip, which helps them attach to feathers or hair.
Their colour can vary from pale to dark grey, which helps them camouflage through the feathers or hairs of their hosts. For the ones feeding on blood, their colour can become darker as they become fully engorged with blood after a meal. The eggs, also called nits, are pale white, if the eggs have a live louse inside, and yellowish if they have a dead louse inside. The adults can have up to 5mm in length, and can be recognised by their colour. The young lice however, are white and really small, and they can be easily confused with dandruff.
Breeding and dietary information
The females can lay up to 100 eggs and need to mate only once. They cement their eggs at the base of the hair follicles and wait for them to hatch. By thoroughly combing your hair, you can remove adults, but eggs as well, and prevent the continuation of the infestation. Lice quickly reach maturity and can reproduce after 28 days, lay eggs, which will hatch in 7-10 days, if located in a warm place. If it is cold, it can take up to 30 days for them to develop and hatch.
When it comes to their dietary preferences, sucking lice are feeding on blood or sebaceous secretions of their hosts, as they get their nourishment from such types of bodily secretions. The chewing lice, however, are scavengers, feeding mostly on dead skin, fragments of hair or feathers or other debris found on the body of their host.
The bites they make in order to feed can be found on the scalp, back of the head and even on the shoulders. If you have the sensation that something is moving on your scalp, if you have trouble sleeping, and if you have a constant sensation of itchiness, then you might have lice. The most exposed to lice are the kids who go to kindergarten, especially girls because they share their stuff more often, and they have longer hair, making it easier for lice to attach to a new host. Personal hygiene has nothing to do with lice, because they do actually prefer a clean scalp.
Depending on the host, the average number of lice can differ. With birds, larger ones tend to have more lice, when infested. The extinction of a specie can also lead to the extinction of its host specific lice. However, lice can also contribute to reducing the host life expectancy, if they are heavily infested. With humans, however, there is no such problem, as lice can mostly cause great discomfort, if infesting the host in a large number.
Lice as pests
Lice don’t jump or fly, they just climb on their host and move around to feed. This is why they normally remain on a single host their entire life. They normally transfer when people get close, and it is also common for them to spread through personal items like hats, towels or brushes. As pests, they are a becoming a bigger problem because they are starting to develop a tolerance to the products used to get rid of them. That is why people are going back to home remedies that are safer for children. However, when using chemical treatments against lice, carefully apply them according to the indications on the packaging, as strong solutions can end up causing rashes on the skin, if not used properly.
If you think you might have lice, then the best choice is to use a fine-tooth comb and brush your hair with it, as you will see lice caught in it. Wash the comb in lukewarm water and comb your hair again thoroughly. To get rid of them you will need to use special shampoo and treatments, based on doctor recommendations.
You will also need to wash all your clothes and sheets to make sure any fallen lice will not reattach themselves to you or a new host. You will need to change your brushes and hair accessories, or thoroughly clean them with alcohol, and make sure you keep yourself or the affected person out of contact with other individuals. As a lice infestation can easily spread, it is important that not only you, but your family also goes under treatment, at the first sign of infestation. All household members and other close contacts should be checked and treated if necessary, and it is important to treat everyone at the same time, to make sure no lice remain behind and starts another infestation.
Keep in mind that almost all treatments need to be reapplied after a week or so, in order to kill any newly hatched lice. Do not consider that after one treatment, you are free of infestation. The best thing you can do in order to prevent it from happening altogether, is to reduce or avoid head-to-head contact and to try not to share hats, combs or other such items with others. Preventing an infestation can be difficult, but you can try and contain it, and not let lice spread to the rest of your family members. It is important to know the symptoms of a lice infestations, and how to quickly act against it. For more such details on how to ‘Prevent infestation with Lice’ and ‘How to get rid of Lice’, you can visit our related articles, where you will find advice, solutions, and a list of steps you need to take in order to eliminate a lice infestation.