Silverfish Control Products

Silverfish are silver-grey, cigar-shaped and up to about 15mm long, with three long bristles at the tail, and move in a quick wriggling dart. They are usually seen at night in bathrooms and kitchens, and often turn up stranded in a bath or sink because they cannot climb smooth surfaces. Woodlice are grey, hard-shelled, oval and slow, with visible body segments, and turn up near doors, air bricks and damp walls. Both point at damp, but the treatments differ - see our woodlice control range if that sounds closer.

They feed on starch, which means paper, wallpaper and the paste behind it, book bindings, cardboard and some fabrics. The signs are irregular holes and yellow staining on stored items, along with shed skins and small pepper-like droppings near where they are feeding. They do not bite people - the issue is damage and nuisance rather than any risk to you.

An adhesive surface, sometimes with a lure, placed on the routes silverfish travel. They catch and hold what walks onto them, which reduces numbers and shows you where activity is concentrated. Silverfish follow edges rather than crossing open floor, so placement decides how well they work.

Sticky traps for finding where the activity is and reducing numbers without an insecticide. A powder for the cracks and crevices they shelter in. A spray where you want faster knockdown or a residual deposit along skirting and behind units. Most cases want traps plus one of the other two.

Traps contain no insecticide; the adhesive is the thing to plan around, so site them out of reach. For sprays and powders, follow the label: keep children and pets out until treated surfaces are dry, work powders into cracks and crevices rather than across open floor, and do not treat food preparation surfaces.

Sprays act on the silverfish present at the time, and traps start catching within days. Clearing a population takes longer - expect numbers to fall across two to three weeks - because silverfish keep emerging from harbourage you cannot reach directly.

Two different pictures. If you are seeing them in the same room every night despite treatment, the harbourage has not been reached - silverfish shelter deep in wall voids, under baths, behind tiles and inside airing cupboards, and surface treatment does not get there. Treat into the cracks rather than across the floor. If numbers dropped and then came back, the damp is still there, which is the real driver.

Usually because the conditions still suit them. Silverfish need humidity and will persist wherever they find it - a slow leak under a bath or sink, condensation in an unventilated bathroom, damp in a cellar or behind a cold external wall. Fix the moisture and the population falls away on its own. If you have dried the space out and sightings continue across several rooms, the likely explanation is grey silverfish, sometimes called paperfish, which cope with ordinary household humidity and are not tied to damp in the same way - that is a whole-home harbourage problem rather than a moisture one. Read our guide to getting rid of silverfish yourself for the full sequence.

Two to three weeks with no sightings and nothing new on well-placed traps. Leave one or two traps set after treatment finishes, so you find out early if activity restarts rather than waiting to see one on the bathroom floor.

Where silverfish are appearing across several rooms, where you cannot find the moisture source, or where activity has not dropped after two to three weeks of drying, cleaning and treatment. That last one often points to grey silverfish, which need a whole-home approach rather than the damp-led one that resolves common silverfish.