3. They’re Living in Cracks You Can Seal
Silverfish are nocturnal and hate light. By day they tuck into:
- Baseboards and wall cracks
- The backs of cabinets
- Under sinks
- Inside closets
- Gaps where plumbing enters walls
Seeing them in daylight is a bad sign — it usually means the population has grown enough that they’re being pushed out of their hiding spots. A few live sightings can mean many more out of view.
Sealing gaps with caulk — around baseboards, pipe penetrations, and window frames — cuts down both their hiding places and the routes they use to move between rooms. It also happens to help with moisture and other pests at the same time.
4. They’re Slowly Eating Your Belongings
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Harmless to you, not to your stuff. Over months, silverfish feed on:
- Books, documents, old photographs
- Wallpaper
- Fabric and stored clothing
- Cardboard storage boxes
If you store anything you care about — paperwork, photos, keepsakes, off-season clothes — in a basement, attic, or any damp space, get it into sealed plastic bins rather than cardboard. Cardboard is both food and shelter for them; sealed plastic is neither.
5. Your Ventilation Isn’t Keeping Up
Bathrooms and laundry rooms without real airflow stay damp long after the shower or the wash is done, and that lingering damp is the whole invitation.
Improve it by:
- Running the exhaust fan during and for a good while after showers — and confirming it actually vents outside, not into the attic
- Opening windows when the weather allows
- Running a dehumidifier in chronically damp rooms
- Fixing leaks quickly instead of living with them
