Lice are obligate and very narrowly specialized human parasites. They are absolutely not adapted to life outside his body or on other animals. Only in exceptional cases, lice can live and somehow reproduce in the hairline on the body of some monkeys, but here they feel much worse than in human hair.
On the question of how many live lice without a man, you can give a simple answer - just as much as you can withstand without food. And the question of hunger for lice is very, very acute - usually a louse can not starve for more than 2 days, and only with a decrease in temperature to 10-12 ° C can stretch without food to 10 days.
On a note
The pubic louse is even less resistant to hunger - with normal temperatures of 28-30 ° C it can not last more than 8-9 hours, and after that time it will die if it does not reach the human body. But in the water lice, especially pubic, can survive for two days, and therefore often transmitted from person to person in places of public bathing.
How many live lice, so much they are continuously fed. Head lice eat four times a day, pubic - every 3-4 hours.
From the above considerations it is easy to understand that long to live outside the head and in general - outside the living being - lice can not.
It is interesting
Frequently asked by parents questions like "how many live nits" or "how many live nits without a person" are not entirely correct. Nits are not independent insects, but only lice eggs , each in its shell. Therefore, they do not live, but develop. Without a human, they retain their ability to develop long enough - up to several days.
Specificity of feeding of lice and their dependence on the host
The only food of all types of lice that occur in humans is the blood that parasites suck, piercing the skin between the hair. It is wrong to assume that the lice feed on the hair itself: some think so because the head lice are often found firmly clinging to the hairs.
Such a trick insect does only to not fall from the head during human movements, when combing or washing hair. To feed the parasite still have to go down to the skin, pierce it with its stilettos and suck blood.
Each species and even each subspecies of lice morphologically very well adapted to their habitat. The size and shape of the segments on the paws for capturing hairs, the shape of the body, even the general contours of the abdomen of the insect, is to live on a person and even on a specific part of his body.
For example, some lice live outside the head - the louse has adapted to life on clothes and crawling onto a person's body when he clothes. A pubic louse lays exclusively on pubic hair and underarms. Only in children, pubic louse can infect hair on the head.
Head lice live not only on the head, but can also crawl on the beard of men and even on the eyelashes. Although in general the size of adult lice does not allow them to comfortably parasitize on too short hair.
In general, even on a person, lice do not live long. If the insect does not fall from the head and is not poisoned by a special shampoo or kerosene, in an adult stage the louse lives a maximum of 40-46 days, the nymph develops an additional 15-20 days. In general, a louse lives on the head for about two months, and on the pubic - about six weeks.
But to go to animals human head lice can not. In laboratory experiments, they feed on the body of monkeys, but in nature, primates are almost never found. Therefore, these parasites can not exist outside the person. The exception is only louse-dwelling , who do not live on the human body, but they eat all the same ...
It is interesting
The inability to bear hunger-striking lice are strikingly different from other parasites. For example, bed bugs can starve for months, and mites - even up to several years. Blok in the room can fast for up to 4 months, and at low temperatures - up to 1.5 years. Lice in this respect insects are striking, but instead of starving they received from evolution a high fitness for life on the human body - practically no ectoparasite has such a high specialization.
A louse something to life without a man is not adapted!
The structure of the body and the way of life of the lice testify to the fact that during their evolution they have managed to fully adapt to life on a human being. Their paws have changed in such a way that they can not do anything, except the realization of the hooks by the hair. The rotary apparatus of lice is adapted only for bloodsucking.
But the most suitable is the fitness of the lice's reproductive organs to the human body: the female lays the egg in a copious, sticky shell, and does so only by moving along the hair. As a result, the egg remains attached to the hair. After leaving the egg, the larva immediately falls on the scalp and can feed.
It is interesting
In nature, human lice do not live. Their close species parasitize on primates, but it is the human parasite that is found exclusively on man.
Outside of a person lice live only on his clothes. So a special kind of lice was formed that can no longer live on the head, but are perfectly adapted to life on clothing (louse-lice). Here they lay the nits, they mate here, and for food they crawl over to the human body. Lice that live on clothing have a slightly different leg structure, which allows them to confidently hold on almost any textile products.
It's interesting that lice lice that live outside the human body are not longevous - their adults live as much as head lice - for about 40 days. Once outside the human body, the louse lives up to 3-4 days, and dies of hunger, if a person does not put on clothes.
It is interesting
In laboratories, scientists use the blood of rats to feed lice or simply cultivate them in monkeys. Here every louse lives without a man as much as would live on the person himself.
But lice that live on animals have nothing to do with humans. Accordingly, it is impossible to get infected from pets by these parasites.
Lice in dogs
Dogs are home to specialized canine lice (more precisely - withers). They have somewhat longer stilettos for piercing thicker canine skin, and also paws adapted to be attached to dog hair. Dog lice can not parasitize a person, and even in cases where they accidentally fall on the head or body of a person, die within a few days.
It is interesting
Dog lice are a family of withers, somewhat different from typical lice. But, like lice, they are distinguished by a narrow specialization and can parasitize only one species of animals.
Cat's louse and its features
The so-called cat louse, just like the dog, belongs to the group of withers and is adapted only to parasitism on cats. In all felines, these insects cause severe itching and skin lesions, and can also carry the eggs of dangerous helminths.
For a person, cat lice are not dangerous. Lice that live on cats can not even attach themselves to human hair.
Do lice live on cushions and blankets?
Of course, on pillows and bed linens, lice do not live. At least because here they have nothing to grasp and there is nowhere to put nits.
In some cases, head lice can get on the pillows from the hair of an infected person and stay there for several hours, waiting for the opportunity to again crawl over the person's head. Louse lice can even settle in folds of blankets and sheets, but these insects do not form permanent populations.
But lice can be transmitted through towels, combs and hair bands. To prevent infection, you should first check the hygiene products and the person with whom communication occurs.
Getting rid of lice and nits at home for 1 procedure: