Lice: now there’s a word that terrorises many parents. For others, the word is more evocative of amusement, of leg-ends… Slowly but surely, these little beasts have spread throughout the world.

EACH TO HIS OWN

As Homo sapiens evolved, the forests on our bod-ies shrunk to become scattered patches, and those warmth-seeking invaders known as lice divided themselves into three tribes:
the “pediculus capitis” – head lice, les “pediculus humanus corporis” – body lice, and finally, “phthi-rus pubis”, pubic lice more commonly known as crabs. By separating into three categories or “tribes”, each found its own forest in which to “squat”. Each of these tribes adapted its weapons to each new jungle and set off in conquest of our ancestors.
Even though the louse is happy to pass from one host to another, it is interesting to know that it is not a jumper, unlike other insects such as the flea. Indeed, the louse is a walker, and can only change its lodgings by contact, with hair, clothing, etc.

However, the louse is not interested in humans alone. Animals can be paradise for lice, thanks to their furry forests. Indeed, François-Xavier Pajot, species systematician at the French Institute of Research and Development, has over twenty years of work shown that many animals provide accom-modation to lice. For example, monkeys and goril-las (which also host pubic lice), warthogs, ante-lopes, squirrels, wolves, dogs and even birds…

STUDS

As soon as it finds favourable conditions, the louse reproduces at maximum speed. And when it comes to sex, the louse is a real stud. With its two pairs of testicles and its penis, the male louse de-votes a great deal of its life to mating. And its at-tributes are rather disproportionate: on a human scale, its testicles would weigh 5 kg and its erect penis would be the size of a thigh. In action, the louse is capable of fertilising 18 females one after the other, and the sexual act can last close to four hours – in all imaginable and possible positions. The female louse lays eggs at the rhythm of four to nine per day. In other words, about 100 to 400 eggs are produced by a single louse during its life-span of about one month. At birth (at the base of the hair close to the scalp), the young lice hide from the light and will pass through three stages before developing into adults measuring about 4 mm.

A PERSISTENT LITTLE BEAST…

Lice can sense a variation in temperature of one third of a degree centigrade, and will leave a body in case of fever or hypothermia. They are covered in an impermeable cuticle and breath through four-teen stigmata or respiratory pores. When air quality deteriorates or conditions become unfavourable, lice are able to close their pores and thus resist chlorinated water and normal hair washing for sev-eral hours. This is why head lice can be found on clean people. Feeding on blood is vital to the louse: it partakes of several meals per day. On a human scale, the louse ingests 45 kg of blood each day, and it takes three hours to digest its meal. These bloody meals are painless for the host because the louse uses an anaesthetic; its teeth can tear flesh without causing pain.

Head lice do not transmit diseases, but represent a physical nuisance, because they cause itching. In general they are not found in great numbers on any single head, no more than a dozen, even though exceptional infestations of up to a thousand lice on one head have been recorded. In any case, thanks to their oversized pincers, these little crea-tures do not easily abandon their homes, hanging to the hairs as tightly as they can.

REWRITING HISTORY WITH LICE

Throughout the centuries, lice have accompanied men in their migrations and have thus invaded all the continents.
For the Brazilian professor Adauto José Gonçalves de Araùjo of the Oswaldo Cruz Foundation, lice are man’s oldest companions. Indeed, he has discov-ered a louse more than 10,000 years old. The study of lice in mummies has proven to be an ex-cellent means for studying the migratory move-ments of prehistoric humans. In this way, through his understanding of the origin of a number of eggs, the professor was able to retrace the history of the populating of America by proving that the Amerindians arrived with their lice, not only via the Bering Straits but also by sea.
Further proof that lice are everywhere: lice have also been found in Greenland in the hair of several desiccated cadavers preserved in ice since the 16th Century.

LICE LEGENDS

Having accompanied humans throughout history, lice are naturally omnipresent in legends and tradi-tions worldwide… whether it be among the Inuit, Indians, Moslems or pre-Columbian civilisations.
The louse – a name given to certain animals by the Inuit, a symbol of hunting success among the Ton-gouse and of luck among Moslems, a means of payment in pre-Columbian civilisations (the poor paid their taxes in sacks of lice) – has accompa-nied humans through every era and on all conti-nents.

In Greenland, there are many legends and stories referring to lice. At school, children do not learn the story of Little Red Riding Hood but that of a little girl Poorustini who loved lice so much, that she ate them!
Another well-known children’s story: the legend of the sea goddess. The sea creatures are in fact born of lice lost by this divinity. The sea goddess ensures that society functions correctly. If the vil-lagers misbehave, the sea goddess becomes in-fested with lice and the hunters return empty-handed. By combing the hair of the goddess, the hunters send back into the water the sea creatures represented by the lice. It is from this legend that the divine importance of delousing sessions in Greenland originates. Such sessions are also pre-sent in many other civilisations.

DELOUSING AND SOCIAL TIES

Whether in humans or animals, delousing has be-come a ritual that enables the reinforcement of so-cial ties.

In animals, delousing is often a game and reflects the true symbolism of the louse. This is principally the case among primates, for whom delousing, also called grooming, plays more a social than a hygienic role. Practiced at any time of the day and lasting up to several hours, the aim of grooming is to strengthen group cohesion. It also often encour-ages maternal cooperation between females and respect for the hierarchy. It is even a pleasurable experience for apes, which delouse one another even when they have no lice. A pleasure that hu-mans have tried to exploit: in Portugal, apes were once trained to delouse humans.

Among humans, "grooming " also exists. There are numerous civilisations in which people enjoy look-ing for lice.
In France, in Brittany at the beginning of the 20th Century, delousing sessions were a common activ-ity, almost daily and often familial. The Breton cul-ture is impregnated with this ritual that is immortal-ised on postcards.
Today, delousing is still practised among Pygmies. This community announces grooming sessions with a ritual louse dance called the “Isengue dance”. Using principally their fingers for delousing, these sessions are also a good way of getting members of the opposite sex together, to form couples and to touch each other. The whole com-munity participates in this ritual, and each member has a function: while the adults delouse, the chil-dren count the lice and the elderly make soap, shampoo and lice combs…

Lice combs are Barbara Thorne’s passion. This American has succeeded in putting together a unique collection comprising over 100 examples. But for Barbara, the American comb collector, the perfect comb has not yet been invented. So she has patented a design for a revolutionary comb composed of three different combs adapted to all the phases of the louse’s development.

HEAD LICE AND GASTRONOMY

Closely related to delousing sessions, many civili-sations have regarded lice as a source of nutrition. Even though we know little about the louse’s calo-rie content, it would seem that some find them de-licious. Considered by some to be an extremely fortifying nourishment, lice have sometimes been found in the stomachs of cadavers and in the ex-crement of mummies. Principally, among Amerin-dians, Eskimos and Inuits… For others, such as the Waicas Indians, lice were even considered an exquisite luxury food (the equivalent of caviar).

LICE TABOO

Though man’s oldest companions, lice remain an enormous taboo in contemporary society. We never talk about them and when we do, it is a shameful subject. The lice taboo started at the end of the 19th Century with advances in hygiene and the arrival of the first insecticides. The existence of these products marginalized those who still had lice, which is how the feeling of shame associated with lice originated. But lice are not aware of social taboos and attack all heads regardless of social stature or culture.
Some people have decided to attack not just the lice but above all the social taboo that they repre-sent…

Doctor Catherine Combescot of the University of Tours is trying to find new products to combat lice more effectively. To test and have approved a new molecule, she travels the world to collect lice wherever the infestation rates are highest. The first phase of her research consists of having the lice at her fingertips to better evaluate their resistance capabilities. For here lies the problem: lice are be-coming increasingly resistant to existing products. This research is imperative because even if fewer people are affected by the lice problem than previ-ously, the recorded cases are becoming more chronic and more severe. But Catherine’s combat does not stop here because she also visits schools to meet children, with the aim of informing them about the tiny creatures that sometimes take up residence in their locks.
Yves Poye, director of a primary school in a Pari-sian suburb, is among those who have welcomed Catherine. He too is active against the social taboo of lice infestation and has mobilised the media most notably. Television and radio shows, plays and songs are ideal vehicles for transmitting his anti-taboo message.
The battle that all these people are waging is on a par with the prejudices associated with lice: long and difficult but solid.

BODY LICE, KILLER LICE

Whereas head lice are inoffensive and responsible only for daily irritation, the case of the body louse is very different, because it is a vector of disease.
All the great armies have been decimated by ty-phus, a disease transmitted to humans by lice while it feeds on their blood. During the Second World War, many epidemics raged with dramatic effects. Consequently, a veritable war within the war was organised against lice with the installation of « industrial delousing stations » where men and their clothing were disinfested with great zeal. In Japan, the American occupation troops went as far as treating prisoners of war with DDT with the same precision. Afterwards, the use of this product was strongly criticised because of its side effects, but the harm had already been done…

In Russia, body lice have also caused great dam-age. In 1917 there were 30 million cases of typhus declared and three million deaths for European Russia alone.
"Either socialism will defeat the louse, or the louse will defeat socialism." (Lenin)
It became rapidly obvious that lice were the enemy of the people and following Lenin’s impetus, disin-festation centres popped up like mushrooms. To-day, as the number of homeless people in Saint Petersburg multiplies, doctors fear new epidemics of disease transmitted by lice such as trench fever and typhus. The victim can be contaminated while the louse is feeding on his blood. But the disease is transmitted essentially through the contact with the louse’s infected excrement when the victim scratches himself raw.

Today, in France too, body lice remain a problem for people living in precarious conditions, notably the homeless and illegal immigrants. Fortunately, they receive help in their daily combat. Françoise Beauvais is such a helper, now retiring after 33 years of loyal service at the therapeutic baths of the Saint Louis Hospital in Paris. Although more and more people come to this place, informed of its existence by word of mouth, Françoise will not be replaced, through lack of funds.

LICE TO COMBAT LICE ?

Today, some scientists seek ways of using lice for therapeutic ends. In Brazil notably, where homeo-pathic lice appear to be a solution to numerous problems in animals, and perhaps soon in hu-mans…
Arenales is a small Brazilian firm specialised in the development of homeopathic products based on lice to combat lice infestations in animals such as poultry, horses and dogs. The granules made from lice are exported throughout South America. The future looks rosy for this company whose turnover increases by 300% each year.