You switch on the bathroom light late at night and something small, silvery and fast darts across the floor and disappears under the nearest skirting board. Silverfish are among the most common insects found in Norwegian homes, and while they are harmless to people, few of us enjoy sharing the house with them. In larger numbers they can also damage paper, books, photographs and textiles.
Getting rid of them starts with understanding why they are there in the first place. A few insects now and then is normal, but a growing population is usually a signal about the indoor environment itself. If the numbers keep rising despite your own efforts, a professional company such as Skadedyrvakta can map the extent of the problem and treat it at the source rather than one insect at a time.
Why silverfish appear
Silverfish thrive in darkness, warmth and above all moisture. Bathrooms, laundry rooms, kitchens and basements are their favourite habitats, and they feed on starch and sugar found in paper, cardboard, glue, crumbs and dust. A home with high humidity, plenty of stored cardboard and undisturbed dark corners is close to ideal for them.
Signs the problem is growing
Seeing them regularly in daylight, finding them in several rooms, or discovering small irregular holes and yellowish stains on paper and textiles all suggest the population is well established. Tiny black droppings, like specks of pepper, along skirting boards and inside cupboards point in the same direction, and so does finding insects of clearly different sizes, since that means several generations are living and breeding in the home.
What you can do yourself
Start with moisture. Ventilate the bathroom properly after showers, fix dripping taps, and consider a dehumidifier in damp basements. Vacuum thoroughly along skirting boards and behind furniture, seal cracks and gaps where the insects hide, and move paper and cardboard storage into sealed plastic boxes. A few sticky traps placed along walls in the affected rooms will show you whether the numbers are rising or falling, which is useful knowledge whatever you decide to do next. Reducing food, moisture and hiding places will slowly starve a small population out.
Common silverfish or the long-tailed kind?
Norway has two lookalikes worth telling apart. The common silverfish depends heavily on damp rooms, so it stays close to bathrooms, kitchens and basements, and drying the home out goes a long way toward controlling it. Its long-tailed relative, which has spread rapidly through Norwegian buildings in recent years, tolerates normal indoor humidity and therefore turns up in living rooms, bedrooms and offices as well. It is slightly larger, has longer tail bristles, and populations grow steadily rather than disappearing in winter. The distinction matters because it decides how far moisture control alone will take you.
When professional help makes sense
Some infestations, particularly of the long-tailed kind, are hard to clear with household measures alone. Professionals use sticky traps to map where the insects are concentrated, then apply targeted bait in exactly those zones. This approach is effective and uses minimal amounts of product, but it requires patience, since results build over weeks as the bait works through the population.
The silverfish is an ancient insect that existed long before humans built houses, so complete eradication from the world is not the goal. Keeping your own home dry, clean and short of hiding places is, and it is entirely achievable. Do that consistently, and the silvery flash across the bathroom floor becomes a rare event rather than a nightly routine.
