A newly completed building appears clean, dry, and free of pests. It is therefore all the more unsettling when, shortly after moving in, elongated grayish-silver insects run across the floor or disappear underneath skirting boards when the light is switched on.
They are often paperfish. Their presence is not an indication of poor cleanliness. Rather, new buildings may combine several conditions that make it easier for these insects to establish themselves: a consistent indoor climate, numerous joints and cavities, locally elevated humidity, and an abundant supply of cardboard and starchy materials.
Anyone who identifies paperfish in new buildings at an early stage, documents their spread, and systematically investigates possible causes can prevent isolated findings from developing into a persistent infestation.
What are paperfish?
Paperfish are wingless, predominantly nocturnal insects. Their elongated bodies taper toward the rear and appear gray to silvery. Their long antennae and three long tail appendages are particularly noticeable.
During the day, these light-avoiding insects hide in cracks, joints, cavities, and other sheltered areas. When the light is switched on, they usually quickly flee underneath skirting boards, furniture, carpets, or coverings. As a result, an infestation often goes unnoticed for a long time.
Paperfish feed, among other things, on starchy and sugary substances. Possible food sources include:
- Paper and cardboard
- Wallpaper and wallpaper paste
- Books, pictures, and documents
- Stamps and collectibles
- Packaging materials
- Crumbs and other food residue
In the event of a more severe or long-standing infestation, feeding damage may occur to paper, wallpaper, books, and stored documents.
Identifying paperfish and distinguishing them from silverfish
Paperfish are often confused with silverfish. Correct species identification is important, however, because their lifestyles, preferred areas, and appropriate control measures differ.
Typical characteristics of paperfish include:
- A rather gray-speckled, less shiny body
- Especially long antennae and tail appendages
- Rapid escape behavior when exposed to light
- Presence in living rooms, workspaces, and storage areas
- Activity along skirting boards, wall connections, and built-in fixtures
Silverfish, by contrast, are more commonly found in damp rooms such as bathrooms, kitchens, or laundry rooms. Paperfish are not exclusively associated with such damp areas and can also spread in living spaces with a typical indoor climate.
Since identification based solely on a brief sighting can be difficult, photos should be taken whenever possible or captured specimens should be examined by a professional.
Why do paperfish occur particularly in new buildings?
A paperfish infestation in a new building can rarely be attributed to a single cause. Usually, several structural and usage-related factors interact.
1. Residual moisture and structural cavities as key causes in new-build properties
During construction, screed, plaster, mortar, paint, and other building materials introduce moisture into the building. Even when surfaces already appear dry, residual moisture may still be present in building components, junctions, and poorly ventilated areas of the new-build property. This can promote a favorable local microclimate, but it is not the sole cause of an infestation.
At the same time, modern construction methods provide numerous protected hiding places where paper silverfish prefer to stay. These include, in particular:
- Floor and wall junctions and gaps
- Cavities behind cladding and skirting boards
- Service shafts and cable and pipe penetrations
- Gaps within walls and floors and beneath built-in fixtures
- Hard-to-access, poorly ventilated areas in the building
Paper silverfish can spread unnoticed within these structures and remain active across several rooms. Visible insects therefore often represent only a small part of the actual population.
3. Boxes and building materials can introduce insects
Paper silverfish can enter a building with packaging, building materials, furniture, books, or other stored items. Particularly during construction and moving in, large quantities of boxes and materials are transported, temporarily stored, and distributed among different rooms.
Moving boxes provide the insects with both food and protected places to stay. If they remain in storage rooms, basements, or rarely used rooms for extended periods, an introduced population can remain undetected for a long time.
Unneeded cardboard packaging should therefore be removed promptly. Important documents and collections can be stored more securely in tightly sealed containers.
4. A consistent indoor climate promotes unnoticed spread
Well-insulated new-build properties often have relatively constant temperatures over extended periods. Together with protected cavities and accessible food sources, this creates stable conditions in which paper silverfish can survive and slowly spread.
Because these insects are mainly active at night and hide during the day, it can sometimes take weeks or months before residents notice an infestation. A single sighting is not yet proof of a large population. However, repeated findings in several rooms or gnaw marks on paper materials should be taken seriously.
How can an infestation be identified?
The following observations may indicate a paper silverfish infestation in a new-build property:
- Repeated sightings of grayish-silver, elongated insects
- Rapid escape reactions when the light is switched on
- Insects along skirting boards and wall junctions
- Findings behind furniture, under carpets, or in storage rooms
- Gnaw marks on paper, wallpaper, books, or pictures
- Catches on suitable monitoring surfaces
Sticky traps are primarily used to determine the extent of an infestation. They help identify activity hotspots and monitor changes over a specific period. The traps alone are generally not sufficient to completely eliminate a larger population.
Are paperfish in a new building dangerous?
With paperfish, the main concerns are not health risks but their potential spread and damage to materials containing starch or paper.
Those particularly at risk include:
- Books and files
- Photos and pictures
- Wallpaper
- Stamps and collections
- Cardboard boxes
- Stored documents
- Archives and library collections
In buildings containing valuable documents, works of art, or extensive collections, a professional assessment should be carried out as soon as the first signs appear.
How can residents control paperfish in a new building?
In the case of individual findings, residents can initially implement several preventive and supportive measures.
Document the infestation
Record the date, time, and exact location of every sighting. Photos, videos, and the results from monitoring traps used can make subsequent assessment easier.
It is also advisable to mark the findings on a simple floor plan. This makes it clear whether activity is limited to one room or already affects several areas of the building.
Check the indoor climate and possible moisture problems
Check the relative humidity with suitable measuring devices. If levels remain elevated for an extended period or there are visible signs of moisture or building damage, the cause should be professionally assessed.
Regular ventilation and sufficient air exchange support drying. In cases of high construction moisture, professional building drying or further building-physics investigations may be necessary.
An existing ventilation system does not automatically protect against moisture problems. What matters is that it is set correctly, operated properly, and maintained.
Reduce paper, cardboard, and food scraps
Remove moving boxes, packaging materials, and accumulations of paper that are no longer needed. Store important documents and collections in tightly sealed containers whenever possible.
Regular vacuuming reduces crumbs, dust, dead insects, and other accessible food sources. Particular attention should be paid to edges, skirting boards, and areas under and behind furniture.
Limit access routes and hiding places
Open joints, cracks, and cable and pipe penetrations can be sealed after a professional inspection. This reduces hiding places and makes movement between rooms more difficult.
However, before carrying out extensive sealing work, it should be clarified where the insects are actually active. Otherwise, important areas of infestation may be overlooked.
Why Home Remedies Are Often Not Enough
Vacuuming individual insects can temporarily reduce visible activity, but it does not eliminate the population in cracks and cavities.
Simply reducing humidity is not always sufficient either. Unlike common silverfish, paper silverfish can also occur outside distinctly damp areas. If food sources, hiding places, and connections between rooms remain, the infestation may persist.
The indiscriminate application of sprays or other products to all surfaces is not recommended. Such measures often fail to reach hidden insects, can make it more difficult to assess the infestation, and are not automatically suitable for every area of a building.
Advion Paper Silverfish Gel is considered one of the most effective solutions on the market and impresses with its nest effect. This means that it targets not only individual insects but also hidden populations in their hiding places.
Who is responsible for paper silverfish in a new building?
If paper silverfish appear shortly after moving in, the question of responsibility often arises for residents, landlords, property managers, developers, or other parties involved.
A blanket assignment of responsibility is not possible. Among other things, the following are decisive:
- the time of the first observation
- the extent of the infestation
- possible moisture or construction defects
- verifiable routes of introduction
- the affected areas of the building
- measures already carried out
Residents should therefore document findings at an early stage and report them to the responsible authority. The date, location, number of insects, photos, monitoring catches, moisture readings, and any recognizable material or construction damage should be recorded.
A professional infestation assessment can help put the situation into perspective. However, it does not replace a legal assessment of liability in the specific individual case.
Correctly assessing paper silverfish in new buildings at an early stage
Paper silverfish in new buildings are not proof of poor hygiene. Several favorable conditions often come together: unnoticed introduction, protected cavities, a stable indoor climate, starchy materials, and locally elevated moisture.
The key is not merely to remove individual insects. The species should be reliably identified, the extent of the infestation documented, and the building inspected for potential moisture problems, hiding places, and pathways of spread.
Deepen your practical knowledge in Online training course “Expertise: Paper Silverfish – with Certificate” and learn how to reliably identify paper silverfish, systematically document infestations, and professionally plan appropriate measures.
Use biocides safely. Always read the label and product information before use.
