Grey silverfish: what to do when you have them

Have you spotted small, fast insects with long tails darting along your skirting boards at night? You are far from alone. Grey silverfish have become one of the most common household pests in Northern Europe — especially in newer, well-insulated buildings. The good news: you can get rid of them without a drop of poison.

Step 1: Get a picture with traps

Before anything else, find out how many you have and where they live. Pitfall traps do both jobs at once: they catch the insects, and the number in the cup tells you whether this is a small problem or a serious one — and whether your efforts are working.

Step 2: The four-part plan

1. Set traps immediately. Place them where you have seen activity and leave them alone. One minute each to set up, working around the clock with no chemicals — safe with children and pets.
2. Remove their food. Grey silverfish digest cellulose, so cardboard and paper are a buffet. Keep boxes off the floor; swap cardboard storage for plastic boxes.
3. Seal cracks and gaps. They shelter around skirting boards, pipe penetrations and under floor trim. Sealing the obvious ones makes your home far less attractive.
4. Track progress. Most people see a clear drop within 2–3 weeks. Keep going until the catch count hits zero, then leave a couple of traps as an early-warning system.

Where to place traps

• Flat against skirting boards — they travel along edges, not across open floor
• Behind the toilet and under the sink
• In the utility room and any storage area
• Near cardboard boxes or stored paper
• Not in the middle of a room — a trap there catches almost nothing

Grey silverfish or common silverfish?

The two are constantly confused, but they behave differently — and the same traps work on both.

More detail in our guide on telling silverfish and grey silverfish apart.

Frequently asked questions