You switch on the bathroom light in the middle of the night and spot a little silvery bug darting into a gap in the tiles. It's a silverfish. If you're wondering how to get rid of silverfish in your home, the good news is that it can be done, and without spraying insecticide everywhere. These insects don't bite or spread disease, but they're a sign of a damp problem and, if they settle in, they can damage paper, books and the odd piece of clothing. Here's why they appear, which home remedies really work and when it's worth calling in a professional.
What silverfish are and whether they're dangerous
The silverfish (Lepisma saccharina) is about a centimetre long, with an elongated body covered in silvery scales and three bristles at the tail end. It's nocturnal, shuns light and moves in a very fast zigzag that looks like a fish swimming, hence the name. It can live for several years, so just a few of them are enough to keep the problem going.
They don't bite people or pets and don't transmit disease. The damage is to your belongings: they feed on starch and cellulose, meaning paper, cardboard, bookbinding glue, wallpaper, crumbs and fabrics such as cotton or linen. Many homes also get the grey silverfish (Ctenolepisma longicaudata), which is slightly larger and can survive in drier conditions; you deal with it the same way.
Why you have silverfish in your home
There are almost always three factors behind it:
- High humidity. They thrive when relative humidity is above 70%. That's why they're common in bathrooms, kitchens, basements and storage rooms.
- Hiding places. Loose grout, gaps behind skirting boards, cracked tiles and the space under the sink.
- Easy food. Cardboard boxes, piles of newspapers, badly sealed flour or cereal and food scraps.
Autumn is when you see them most: we air the house less, dry laundry indoors and condensation soars. If that sounds familiar, it's also worth reading our guide to damp in the house in autumn, because tackling humidity is half the job. And what if they turn up in your bed or bedroom? They're not after you: there are usually papers, boxes or a damp wall nearby.
How to get rid of silverfish step by step
- Find the source. Turn off the lights, wait a quarter of an hour and check the grout, the back of the toilet, the vanity unit and the skirting boards with a torch. Wherever you see the most, that's where they're nesting.
- Bring down the humidity. Air the room for ten minutes after every shower, use the extractor fan, fix any drips and, if needed, run a dehumidifier. A cheap hygrometer will tell you whether you're below 50-60%, the point at which they stop feeling at home.
- Vacuum thoroughly. Run the crevice tool along cracks, skirting boards and shelves. This removes eggs and insects. Throw the bag away or empty the container outside.
- Cut off their food. Swap cardboard boxes for plastic ones with lids, keep flour, pasta and cereal in airtight containers and don't let newspapers pile up.
- Seal the cracks. A little silicone or filler in joints and along skirting boards takes away their hiding places and stops them coming back.
Natural home remedies to get rid of silverfish
These remedies work best once you've brought the humidity down. On their own they reduce the population, but they won't wipe it out.
| Remedy | How to use it | What it's for |
|---|---|---|
| Jar trap | A glass jar with masking tape wrapped around the outside and a piece of bread inside. They climb up the tape, fall in and can't climb back up the smooth glass. | Catching them and gauging how many there are |
| Damp newspaper | Roll up a newspaper, dampen it, secure it with an elastic band and leave it out overnight. In the morning, bin it in a sealed bag. | Catching insects |
| Diatomaceous earth | A thin layer of food-grade powder in cracks and behind furniture. It only works when dry; replace it if it gets wet. | Killing them on contact |
| Lavender, cedar or cloves | Sachets or blocks in wardrobes and on shelves. | Keeping them away, not ending an infestation |
Bicarbonate of soda mixed with sugar is a popular remedy, but the results are patchy; diatomaceous earth is more reliable. Boric acid does work, but it's toxic if swallowed: never leave it within reach of children or pets.
Silverfish in the bathroom, kitchen and wardrobes
In the bathroom
It's their favourite spot. Check the sealant around the bath and shower tray, don't leave damp towels piled up and keep the door open after showering so the room dries faster.
In the kitchen
Look under the sink for small leaks, clean crumbs out of cupboard corners and keep dry foods tightly sealed.
In wardrobes and on shelves
Store clothes clean and fully dry, avoid cardboard boxes and leave a small gap between books and the wall. The same measures help against other fabric pests, as we explain in our guide on how to get rid of clothes moths.
When to call a professional
If after four to six weeks of these measures you're still seeing several every night, or they've started damaging documents or valuable books, call a pest control company. Choose a certified, properly licensed firm and ask to see proof of their registration before you hire them.
In short
To really get rid of silverfish, you have to tackle the root cause: less humidity, fewer hiding places and no food within reach. With that and a couple of homemade traps, they usually disappear within a few weeks. And if you're getting your home ready for autumn, take a look at Velia Select's products: practical ideas for the home and pets that make everyday life easier.