Inici 8-12 years What are lice?

What are lice?

by escoles_admin

If your head itches you may have lice.

If your head itches, your doctor or pharmacist may say that you have Pediculus humanus capitis. But don’t worry; this means you have LICE!!!!

What are lice?

It may be stated that lice are the parasites that most often visit schools.

Since lice have probably also visited your school, you may already know a lot. or maybe not. This is why we will explain how to get rid of them.

Lice are hematophage insects (they feed on blood) and parasites(they live at the expense of others) which make a home out of the hair of people (Pediculus humanus capitis). Some lice also install themselves in clothes and on the body (Pediculus humanus corporis), while others do so in the pubic region (Phthirus pubis). But for the time being we won’t speak about these last two types.

What is a louse like?

As we have already mentioned, lice are insects, and like many insects, they are small. A louse typically measures between 2 and 4 mm, and although they are small indeed, they are equipped with all they need. The males are smaller than the females.

They are elongated in shape and gray, white or yellow in color. When full of blood, they turn red. As we have already mentioned, lice are hematophage insects, and as such feed only on blood.

Learn about the body of a louse


The head is much smaller than the body, and has eyes, two antennas and a oral apparatus. This oral apparatus is a small bulge located on the anterior part of the head.
The upper lip is a minute trunk-like structure with which the louse secretes saliva and an anticoagulant substance to facilitate the sucking of blood. We could say that lice are like little vampires!!?

The trunk has three pairs of legs that end in a grasping hook for attaching to the hair or clothes. In the females it is “V”-shaped, while in males it is rounded in the form of a “U”. When the females have attached to the hair or clothes, they begin to lay eggs (nits).

On the sides of the abdomen lie the respiratory orifices and thegenital apparatus. The females have a pair of gonophores (an apparatus that secretes a cement-like substance) that allow them to affix to hair and clothes and secrete a fluid for fixing the eggs to the hair (generally at the root). This liquid is resistant to both water and soap, which is why it is so difficult to get rid of lice.

I bet this puzzle is easy for you to do!!!

How is a louse born and how does it live?

The life of a louse has three stages: egg or nit, nymph and adult. Lice live for between 30 and 40 days (If you don’t get rid of them earlier!).


A female louse lays about 10 eggs a day, which means approximately 200 eggs in her lifetime.

Between 5 and 11 days after laying the eggs (maturation period), the nymphs appear. After three successive transformations, the nymphs in turn become adult lice within approximately 15 days.

The average life cycle of a louse lasts 18 days.

The warmth of the human body (37ºC) is very favorable for the development of lice. The adults feed on blood which they suck in very small amounts but very frequently. The saliva which the louse places in the small bite wound causes the irritation and itching.

Although lice are very small, they can be seen quite clearly. Even the nits or eggs, which are even smaller than adult lice (0.6-1 mm), can easily be seen. Sometimes they may look like dandruff, though unlike in the case of dandruff, if you shake or brush your hair the nits or eggs do not fall off. It is also possible to distinguish between full and empty eggs. The full eggs are white and do not shine, while the empty ones are almost transparent.

Have you ever been visited by a louse?

Let’s see what must happen for a louse to reach your scalp. If just one boy or girl in school has lice, the whole school can become affected, if the required actions aren’t taken.

Lice infestation is very common in the hair of boys and girls between 6 and 10 years old..

How do lice go from one place (or head) to another? Lice generally move from one person to another by direct contact. This is why measures must be adopted to get rid of lice. In this sense, follow the instructions of your pharmacist, teachers or parents.

How can lice move around in the hair of the children at school? Lice have a very active locomotor apparatus. That is why they can easily move from the head of one child to another.

Other ways by which lice can move from one place to another is in combs and brushes, and/or by sharing hats or caps.

Why does our head itch when we have lice?

  • Itching is the most common symptom produced by lice, and is explained by our allergic reaction to the saliva secreted by the lice when they suck our blood (when they bite us).
  • This is why we spend the day scratching our head when we have lice. And scratching, scratching all day long won’t solve the problem. Indeed by scratching we can cause small sores that don’t help to lessen the itching sensation.

How can we get rid of lice?

When we seem to have lice, the following parallel steps should be taken:

Prevention (to avoid contaminating others): our classmates must be told about the problem, and we must also observe some measures of hygiene:

  • Let our parents examine our scalp, especially behind the ears, at the back of the head, and front region.
  • Wash our hair often: two or three times a week.
  • Comb our hair daily. Clean our comb or brush frequently.
  • Do not pass your personal cleaning items on to siblings or classmates.

Treatment (to eliminate them): Contact pesticides are available that cause the death of lice by paralysis.


Now that you have learned about the life and activities of lice, remember that they must be eliminated as quickly as possible, and above all:

  1. Consult your doctor or pharmacist
  2. Consult your doctor or pharmacist

Note for teachers and relatives:

  • Children without lice do not need to be treated. The parents should watch out for the presence of eggs. This can also be encouraged from school.
  • At school, it is important for all infested children to follow treatment simultaneously, since contagion may occur between infested children who have not yet received treatment and children already treated.
  • Affected relatives are to be treated at the same time, since they may transmit the parasite to healthy children and thus spread the problem throughout the school.

It is advisable for infested children to stay at home and not return to school until effective treatment has been started.


Author: Mònica Carol Torrades

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