The head lice are a small insect measuring between 2 mm to 3 mm long, without wings and with a flattened body dorso-ventrally. Dirty white to greyish white in colour, it takes on a reddish hue when it has taken its blood meal.
The head lice feed exclusively on the blood of its human host.
The head lice live almost exclusively on the heads of humans. It is visible around the ears and near the nape of the neck. In cases of a large infestation, it can be found in the beard, mustache, eyebrows and eyelashes.
The female lays between 50 to 100 eggs on the hair. The laying takes place especially at night, it produces a secretion on which it deposits the egg to fix it at the base of a hair, near the scalp, while drying, this substance forms very resistant cementum.