Skip The Insecticides: Here's A Simpler DIY Solution To Repel Silverfish

Spotting a scuttling silverfish (Lepisma saccharina) is never pleasant, and these annoying insects never seem to let up, despite your best efforts. If you're trying to avoid toxic commercial pesticides in favor of something more natural, there's another option to try: peppermint. Research behind peppermint oil suggests it can help deter certain insects due to its pungent fumes, depending on the concentration and exposure method (ingestion versus contact). But research on silverfish is still fairly limited and has barely scratched the surface. That said, peppermint oil is still widely recommended by pest control professionals as an effective silverfish deterrent and is often touted as an effective way to keep spiders out as well.

In a 2021 study, researchers tested peppermint (Mentha piperita) and neem (Azadirachta indica) oils at three different concentrations to see how effectively they repelled adult silverfish. Peppermint's repellent effect generally increased with both the concentration and the amount of time the insects were exposed to the treatment. After two hours, the highest tested peppermint concentration produced a 46.6% repellency rate, compared with just 6.6% at the lowest concentration. Neem performed even better, reaching 66.6% repellency at its highest concentration after two hours. That said, peppermint may be a more appealing choice for a home, given the distinctive and not altogether pleasant aroma of neem. But set realistic expectations. The research suggests peppermint has potential as a silverfish repellent, not that it will eliminate an infestation, so it's best used as part of a larger strategy for prevention.

To try peppermint oil for your silverfish problem, fill a clean spray bottle with 1 cup of water, 1/4 to 1/2 teaspoon of peppermint essential oil, and 1 teaspoon of mild liquid dish soap. The soap acts as an emulsifier, which helps distribute the oil through the water for a more consistent mixture, but shake it to combine before each use. Spray it around baseboards, door and window frames, cracks, crevices, and other areas where you've spotted silverfish. You can also put peppermint oil on cotton balls and place them near suspected hiding places if you prefer not to apply it directly. Refresh your peppermint every few days as the scent fades.

When working with peppermint oil, note that it may stain fabrics, paper materials, and some finished surfaces, so avoid fabrics and upholstery and do not apply it directly if you're trying to protect books and paper from silverfish. When applying to painted or stained surfaces, always test a small, inconspicuous area beforehand. Peppermint oil is also toxic to cats and dogs when ingested or inhaled and can have harmful side effects in close proximity to small children as well, so don't use it anywhere your pets, infants, and small kids can access it.

Aside from your minty means of prevention, it's crucial to address why silverfish are in your home in the first place. Reduce potential food sources by storing pasta, cereals, flour, pet food, and similar items in airtight containers and regularly vacuuming floors, carpets, and upholstered furniture. Since silverfish thrive in moisture, run a dehumidifier in basements or other damp areas, and keep gutters and downspouts clear so water effectively drains away from your home. Finally, eliminate potential hiding places and entry points by sealing cracks and crevices around baseboards, windows, door trim, and openings around pipes with caulk, spackle, or expandable foam.