They are insects, belonging to the order Zygentoma.

It includes four families with about 370 species. In Europe we find only two families with about 60 species. In Greece about 15 species.

The most common species is Lepisma saccharina of the Lepismatidae family.

Features:

Size: They are usually between 13 and 30 millimeters long.

Body shape: Their abdomen is conical at the end, giving them an overall fish-like appearance.

Color: The newly hatched nymphs are whitish, later acquiring a grayish hue with a metallic sheen.

Anatomical characteristics: They have three large cerci (protrusions) on their abdomen and scales all over their body.

Vision: They have small compound eyes or lack eyes altogether. They lack eyeballs.

Wings: They do not have wings.

Antennae: They have large antennae.

Lifespan: They usually live from 2 to 8 years.

Biology

Most species live in habitats with high humidity, e.g. in the soil among organic debris or under the bark of trees.

There are species that are drought tolerant.

There are herbivorous and omnivorous species.

Species that live near humans can feed on paper, glue, or other starchy substances.

They are nocturnal. During the day they hide under rocks or in the soil. They can move quite quickly.

They show unchanging growth. We may have up to 60 outgrowths.

The ability to reproduce is acquired after approximately 12 molts.

Some species reproduce parthenogenetically.

As a rule, the male places the spermatophore on the ground, sometimes in a network of threads.

The female, following the threads, reaches the spermatophore and transports it to the spermatheca.

Soft-boiled eggs are initially white, but after a few hours they turn yellow or brown. They are elliptical in shape.

The eggs are laid singly or in groups by the ovipositor in cracks or crevices.

The little fish and the man

Some species have adapted to the conditions of human dwellings and have spread worldwide, making them a nuisance or even harmful. The best known such species are Lepisma saccharina and Thermobia domestica.

Lepisma saccharina, as its name suggests, feeds on carbohydrates such as starch, dextrin from glues, as well as various other materials containing polysaccharides such as bookbindings, carpets, clothing, coffee, dandruff, glues, hair, paints, upholstery, paper, photographs, plaster and sugar. They can also consume cotton, dead insects, linen, silk or even their own clothing. In extreme cases, they can even infest leather and synthetic fabrics.

They can survive for a year or more without food, which makes them particularly tenacious.

They are usually not visible, so special traps with small glass jars covered on the outside with paper tape are used to control and record the infestation. The insects climb the tape, fall into the jars, and cannot get out again.

To address them, the following measures are proposed::

Maintaining high levels of cleanliness to limit available food

Avoid moisture and provide good ventilation

Repair of holes, gaps and water leaks

Using dehumidifiers in humid spaces

Application of insecticides when necessary