10 things you didn't know about lice
1. The ears and the nape of the neck are their favorite
These six-legged insects show a clear preference for the nape of the neck, where the hair is usually longer and they usually lay their eggs behind their ears. Specifically, one or two millimeters away from the scalp, where they are kept warm. To prevent the eggs from falling off, their mothers produce a kind of sticky tail. Larvae are born within seven to eleven days.
2. Passing from adults
Infestations usually occur between the ages of three and ten. From ten onwards adults hair produces a high volume of sebum in the hair, this is a fatty substance that lice detest and in turn avoid. This is why there are hardly any cases among adults. Another declared enemy of these parasites are hair dyes, especially those containing ammonia.
3. It's hard to get rid of them
It is best to opt for a combination treatment. The combination treatment aims to eliminate lice and their eggs, with special combs, and also through applying chemical products. Until recently shampoos and lotions contained pyrethrins, an insecticide that can be ineffective if lice have become resistant, which is becoming more and more common. That's why treatments with dimethicone, a kind of silicone that plugs the holes through which the louse breathes, causing asphyxiation and dehydration, have begun to earn points. An effect similar to the one our grandmothers were looking for when they spread mayonnaise on the hair, but more effective.
4. Professional lice killers
In both the United States and Europe, lice exterminators such as The Hairforce have sprung up. Their operators fight the battle against the parasites using a powerful mini-aspirator to extract as many insects as possible. They then squirt hot air into the hair to dehydrate the eggs. And they end up applying a hair conditioner and removing the remaining eggs with a special comb.
5. There are three types of lice
In addition to those in the head - Pediculus humanus capitis-, humans are vulnerable to two other ftirápteros. On the one hand, body lice -Pediculus humanus corporis-, which belong to the same species and usually live in clothes, sheets and towels. They lay their eggs on the textile fibers and only move temporarily to the skin to feed.
They are joined by pubic lice, Pthirus pubis. According to recent studies we were infected by gorillas several million years ago, perhaps by sleeping in the same nests or feeding on their meat. They are usually found attached to the hair of the pubic area, although they can also colonize the hair of eyebrows, eyelashes, beard, moustache or armpits. They are transmitted during sexual contact.
6. Helping science
Knowing the migration patterns of our species is easier with the collaboration of these parasites. Lice have enabled scientists to discover that we humans started wearing clothes 170,000 years ago, long before we left Africa behind to migrate to colder climates and higher latitudes. This date would be impossible to determine from archaeological traces, as it is difficult for a tissue not to disintegrate in such an extended period of time.
7. Dinosaurs also suffered from lice
Dinosaurs were also brought upside down. According to a recent study by the University of Illinois (USA), there is a possibility that these large reptiles were the first living beings to endure their incessant itching of lice.
After studying the genes of 69 lice that affect different modern mammals and animals, Vincent Smith and his colleagues came to the conclusion that they began to diversify before the extinction of the dinosaurs. "Lice are like living fossils; the record of our past is written on them, and they help to reconstruct the evolutionary history of their hosts," they say.
8. They don't jump
Unlike fleas, lice don't jump from one side to the other. They don't know how to fly either. They don't even defend themselves by swimming. But they walk pretty fast, about 30 centimetres per minute on dry hair.
So, the only possible way of contracting lice is, while children play with each other, their hair comes into contact. Or if they share brushes, combs, headbands, and caps. A new trend is also making lice highly contagious for teenagers according to dermatologists. The young hipsters put their heads together when taking selfies with the mobile phone and this is a method in which lice can transfer from one head to another.
9. They love clean hair
Their target is not dirt, but blood and because of this they seem to prefer clean to dirty hair, and straight to curly. Lice locate the veins of the scalp, perforate them and suck the blood, not without pouring a little saliva first to prevent it from clotting. As a consequence, the victim begins to perceive a strong itch that has nothing to do with lack of hygiene. Therefore, insistently washing the child’s head does not prevent him/her from becoming infected.
10. Mating and spreading
These parasites mate once. But it is a very effective copulation, as the female stores the sperm in her body and uses it to produce eggs every day of her life, which normally lasts a month. They usually lay five to ten eggs a day.
