Silverfish: How do silverfish develop? Where are you from?

If a small, silver-colored something whizzes through your living space, it is probably a silverfish that you want to get rid of as soon as possible. But what exactly is that? How are silver fish formed? And above all: How do the strange creatures get into the house? The following article provides precise answers to these questions.

Silverfish in a short portrait

There are around 425 different species of fish worldwide - one of them is the silver fish. All fish belong to a special genus of insects, which is known in technical jargon as a zygentoma. This vast species has inhabited the earth for an estimated 300 million years. This makes the fish one of the oldest animals on our planet. A silverfish life lasts an average of two to five, sometimes even six, seven or eight years.

Optical properties

Silverfish are flat, wingless insects

with conspicuously long, thread-like and touch-sensitive antennae at the ends of the abdomen and abdomen. The main characteristic, however, is the dense scaling, which gives the adult animals their shiny silver appearance. Furthermore, silver fish have small complex eyes. However, the human organ of vision cannot perceive that of its little adversaries. Speaking of small: silverfish, including attachments, can grow up to 22 millimeters long.

Infobox, the main features at a glance:

• Scale color: shiny silver
• Front attachment: 2 touch probes
• posterior appendix: 3 tails
• Length without attachments: approx. 1 cm
• Length with attachments: approx. 2.2 cm

Right name

A question of the right name

If you take it very carefully, it is wrong to call silverfish silverfish. After all, the beings are not assigned to the aquatic animals, but to the insects. In view of the swimming-like movements of the insects, however, it is obvious that we are talking about fish at all.

The scientific name of the silverfish is Lepisma saccharina - and it says it all: translated into German, the term means something like "sugar guest". In fact, the little animal shows great interest in anything that contains sugar. But not only…

Way of life of the silverfish

The way of life of silverfish

People tend to find silverfish disgusting and prefer not to have anything to do with the insects. Nevertheless, it is not uncommon for the animals to sneak into private rooms in order to carry out their everyday lives there. The latter consists essentially of foraging, eating and reproducing.

What silverfish eat

The menu of silverfish is surprisingly diverse. In addition to the sugary foods mentioned, the beings also appreciate starchy substances as well various things that you would probably never guess would be interested in devour. This refers to dead house dust mites, remains of other insects and molds, as well as human skin cells and hair. The fish also like to nibble on textiles and paper. Unlike most other living things, they can digest cellulose.

For example, when a silverfish “grabs” a T-shirt that has been lying at the bottom of the laundry basket for ages and has not been for a long time has enjoyed machine cleaning, he scrapes the surface of the with his tiny mouthpiece Garment. If you suddenly discover small black traces of excrement or yellowish discoloration on the shirt, this indicates that a little fish was at work.

You should also take good care of your books or other important papers. The material is literally found food for the insects. Again they “gnaw” the surface of it and literally graze it. Most of the time the fish nibble around the printer's ink, but sometimes the colored areas have to believe in it too.

Worth knowing: If it is not destroyed by humans beforehand, an adult Lepisma saccharina can survive more than 300 days without any food - that is almost a whole year.

Formation of silver fish

The formation or reproduction of silverfish can best be described with the adjectives “detailed”, “indirect” and “risky”. In the dark, the insects open up the mating behavior. The male starts with a kind of dance. As a result, the male and the female run around excitedly.

The male packs his sperm into a small bundle and deposits it more or less defenselessly on the ground - just building a web of silk threads over it. It then lures its female close to the semen bundle (spermatophore). The silver fish lady slides under the silk web and picks up the valuable cargo with her egg dispenser (ovipositor). The actual fertilization then takes place inside the female.

During their reproductive phase, the silver fish woman lays 50 to 150 slightly brownish colored eggs. Freshly hatched fish do not yet have the typical silver-colored scales. They look more like dark gray to black. Only after the third molt does the metallic sheen become apparent. A silverfish is sexually mature after about the eighth molt. After that, up to four moults per year still occur because the insects continuously grow a little bit.

Interesting: The skin shed during growth also serves as food for the silverfish.

Depending on the environment, the newborns develop into adult, sexually mature silverfish within four months to three years. In a normal household, the process takes about a year. Incidentally, silverfish do not undergo metamorphosis in the narrower sense (transformation of the larval form to the adult stage) and reproduce until they die.

Conditions for a happy silverfish life

Silverfish cannot pursue the activities described under all circumstances. Rather, certain conditions must be met. Only then do the animals have the opportunity to eat happily and reproduce successfully.

Warmth as an essential factor

Warmth is an essential factor for the formation and survival of silverfish. The temperature must be between 20 and 30 degrees Celsius. Otherwise it will be too cold for the insects and they will not feel well.

The importance of moisture

However, heat alone is not enough. In addition, the silver fish need a relative humidity of 80 to 90 percent. With regard to the greed for paper, for example, this means that you do not have to worry about your well-protected books in cupboards and (dry) shelves.

Only those products that have been lying open in a damp environment for a long time or reveal damaged bindings irritate the little creatures. The principle can also be applied to clothing. Silverfish ignore fresh, dry laundry in a clean cupboard. They are only enthusiastic about items of clothing that eke out their existence in damp climes.

Preferred rooms

Preferred spaces of the insects

From the above-mentioned requirements and culinary preferences, it follows that silverfish find quite good living conditions in various rooms inhabited by people. Above all, these are of course the damp rooms - i.e. the bathroom and toilet, if the latter should be housed separately and well heated. The kitchen is also eagerly explored. There the insects prefer to stay under the refrigerator.

How do they get into rooms

This is how the insects get into the house

Okay, so silverfish feel comfortable in human areas. But how do they even get inside a house or apartment?

Cracks and crevices in old buildings

Due to their small size, silverfish have little difficulty getting where they want to go. They fit easily through small cracks, crevices and leaks in the masonry, which are common especially in old buildings.

Windows and doors

Sometimes they do it like humans and gain access to private rooms through open doors or windows. There they check the situation and, based on the food available, decide whether it is worthwhile to stay a little longer.

Silverfish colony

Establishment of a silver fish colony

If the inspection is positive, the silverfish settle in the rooms and breed. A silverfish colony is created. Then you should react at the latest if you do not want to share your home with insects in the long term. Practical tips on suitable home remedies to get rid of the fish can be found here.

Fight silverfish with home remedies

The behavior of silverfish

Silverfish commonly inhabit pipes and water pipes. These areas are humid and warm - and therefore offer the insects optimal living conditions. They usually only move into the rooms of the apartment or house if they discover sufficiently warm, humid corners and dark cracks as hiding places during the day. Speaking of dark cracks: silverfish are dark-tempered animals. They shy away from the light and usually only make the rooms unsafe in the late evening hours, at night and early in the morning.

Enemies of the fish representatives

The silverfish is not only an enemy of humans who absolutely want to get rid of it. The Lepisma saccharina does not get along well with the common earwig (Forficula auricularia) either. In addition, the silverfish always runs the risk of being eaten by a spider.