Silverfish Control in Toronto

Silverfish are the small, teardrop-shaped, silver-grey insects that dart out from behind books, baseboards, and bathroom tiles when you turn on the light. They are harmless to people, but they feed on paper, cardboard, wallpaper paste, book bindings, and natural fabrics, so a real infestation quietly chews through the things you store. They also feed the house spiders in a damp basement, which is why a silverfish problem often shows up first as a spider control Toronto call; typical prices for both are on our pest control cost Toronto guide. The honest fix is not a spray. Silverfish live where it is damp, and until you dry the space out they keep coming back. We treat the harbourage and tell you which leak or humidity problem is feeding them, because that is what ends it. Free inspection, same-day service, two-month guarantee.

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How to tell if you have silverfish

The clearest sign is the insect itself: about 12 to 19 millimetres long, silver or grey, carrot-shaped and tapering to the tail, with three bristles at the back and two long antennae, moving in a quick wriggling dash. You usually see them at night in a bathroom or basement when a light goes on. When you are not seeing the bug, look for the traces they leave:

• Tiny pepper-like droppings, dark specks that look like coarse ground pepper, on shelves, in drawers, and inside stored boxes.
• Yellowish stains and small holes on paper, book pages, wallpaper, and stored clothing, often with the surface layer scraped away rather than eaten straight through.
• Shed skins, thin translucent moults left near their feeding sites, since silverfish keep moulting their whole lives.
• Grazed edges on cardboard, book spines, and the glued seams of boxes where they feed on the starch in the paste.

Silverfish are a symptom of a moisture problem. The insect is what you notice; the damp is what is actually wrong. If you find droppings and yellow stains in a closet or a storage locker, the material in there has already been feeding them for a while.

Where silverfish hide in Toronto homes

Silverfish hide in the dampest, darkest, most paper-rich parts of the home, and Toronto's older housing stock gives them all three. They shelter tight against a surface by day and feed at night, so you find them in:

• Bathrooms: behind the toilet, under the sink, and in the gap behind wall tile, wherever condensation and a slow leak keep things humid.
• Basements: unfinished basements in the Annex, Cabbagetown, the Beaches, and the east-end semis, where old brick and stone hold damp and cardboard storage sits on the floor.
• Kitchens: under the sink, behind the fridge, and in pantries where they get into flour, cereal, pet food, and other dry starchy goods.
• Book and paper storage: bookshelves, filing boxes, and archived documents, a food source and a hiding place at once.
• Around plumbing: inside walls and along pipe runs, which is how they travel between rooms and, in condos and walk-up apartments, between stacked units.

Toronto's older brick and Victorian homes are prime silverfish habitat: humid basements, plaster and paper-backed materials, and decades of stored paper. Condo and apartment bathrooms and kitchens run the same risk wherever a bathroom fan is missing or unused.

The honest fix: dry the space out first

The one thing that ends a silverfish infestation is removing the moisture they depend on. Silverfish need high humidity to survive and breed, so drop the relative humidity and they cannot hold on, no matter what you spray. Before or alongside any treatment, this is what does the work:

1. Run a dehumidifier in the basement and any damp room, keeping relative humidity below about 50 percent. This alone breaks most basement infestations over a few weeks.
2. Fix the leaks. A dripping trap under the sink, a slow toilet leak, a damp foundation corner. Silverfish cluster where the water is.
3. Ventilate. Use the bathroom exhaust fan during and after showers, and if a windowless bathroom has no fan, that is worth fixing.
4. Cut the food and shelter. Move stored paper, books, and cardboard off basement floors into sealed plastic bins, keep dry goods in sealed containers, and vacuum shelf edges and cracks to remove eggs and droppings.

How Insectica treats silverfish

We combine targeted product with the moisture guidance above, because product without the moisture fix is a temporary result. On a silverfish job we:

• Inspect for free to map where they are feeding and, more importantly, where the damp is coming from.
• Apply crack-and-crevice treatment with Health Canada PMRA-registered product placed directly into the harbourage: baseboard gaps, cracks around tile and plumbing, the backs of shelves and cupboards, and wall voids.
• Give you the moisture plan specific to your home: which room to dehumidify, which leak to fix, which storage to move, so the result holds.

Every product we use is PMRA-registered and applied to the label. The work is carried out by Insectica Pest Control, owner-operated, not a franchise, run out of a Scarborough storefront serving Toronto and the GTA, and there is no upsell: if the honest fix is a dehumidifier and a repaired trap under your sink, we will say so.

The other pests that follow the same damp

Silverfish share their damp, hidden habitat with the other moisture-loving pests, so finding one often means the conditions are right for others. If you are also seeing something faster and larger in the kitchen at night, read the cockroach control page, because roaches want the same humid cracks. Ants also follow moisture indoors; the ant control page covers those. For what any of this costs, the pest control cost page breaks it down by pest and home size.

Common questions

Reviewed August 2026.

(365) 217-5987