Will diatomaceous earth harm my pets or family?

Food-grade diatomaceous earth is low in toxicity, but the fine dust can irritate lungs if inhaled. Apply it in thin layers in areas not frequented by pets or children, and wear a mask while dusting. Keep boric acid out of reach of pets and kids, as it is more toxic if ingested.

How long does it take to get rid of silverfish?

With consistent dehumidifying, cleaning, and repellent application, you can expect to see a significant reduction within one to two weeks. Complete elimination may take longer if the infestation is large or if moisture problems persist, because eggs hatch over time.

Can silverfish damage my kitchen?

Silverfish feed on starches and paper, so they can damage cardboard food packaging, paper towels, and wallpaper. They do not bite humans or spread disease, but they can contaminate dry goods with their droppings and shed skins, making food unfit to eat.

Do I need to throw away food that silverfish touched?

Yes, discard any dry goods that show signs of silverfish activity, such as holes in packaging or visible insects. Transfer all unaffected food into airtight containers to prevent further contamination and to remove the silverfish's food source.

How to Kill Silverfish in the Kitchen: Dehumidify and Use Targeted Repellents

Why Silverfish Choose Your Kitchen

Silverfish are small, wingless insects that thrive in damp, warm environments. Kitchens often provide ideal conditions because of steam from cooking, leaky pipes, and standing water near sinks. They feed on carbohydrates and proteins found in starches, paper, cardboard, and even certain food residues, making your pantry and cabinets attractive.

Unlike ants or cockroaches, silverfish are nocturnal and shy, so you may only see them when you turn on a light at night or move stored boxes. Their presence is less about dirt and more about moisture and available food sources. Before you start killing them, it helps to understand that controlling humidity and removing their food supply are the foundation of any effective treatment.

A silverfish insect on a kitchen counter near a sink

The Worked Scenario: A Damp Pantry with Silverfish

Imagine a typical kitchen: a pantry with cardboard boxes of pasta, cereal, and paper napkins. A small pipe under the sink has a slow leak, and the room’s humidity hovers around 65%. At night, you see two or three silverfish near the baseboards and inside the pantry. This scenario is common, and the following steps show how to eliminate them in about two weeks.

Your goal is to reduce humidity to below 50%, remove silverfish food sources, and apply targeted repellents and traps. You’ll need a dehumidifier or moisture absorber, a vacuum, airtight containers, and a few store-bought products like diatomaceous earth, sticky traps, and boric acid powder. No single step works alone; combining them is what breaks the cycle.

Step 1: Dehumidify and Fix Moisture Problems

Silverfish cannot survive long in dry conditions. Start by running a dehumidifier in the kitchen, especially if the room feels humid or you see condensation on windows. Aim for a relative humidity below 50%. If you don’t have a dehumidifier, place moisture-absorbing products like silica gel or calcium chloride in cabinets and corners, and replace them as directed.

In the scenario, the leaky pipe under the sink is the main moisture source. Fix it with a wrench or call a plumber, then dry the area thoroughly. Wipe down counters and the sink basin every night to remove standing water. Ventilate while cooking by using the exhaust fan. These changes alone make the kitchen far less inviting, and within a few days you should see fewer silverfish.

Run a dehumidifier or place moisture absorbers in the pantry and under the sink.
Fix any plumbing leaks and dry wet areas completely.
Wipe down counters, sink, and floor areas daily to remove water residue.
Use an exhaust fan or open a window during and after cooking to reduce steam.

Step 2: Remove Food Sources and Hideouts

Silverfish eat starchy materials, including paper, cardboard, glue, and some food crumbs. In the pantry, remove all cardboard boxes and transfer dry goods like pasta, cereal, and flour into airtight glass or plastic containers. This cuts off their food supply and also makes it easier to spot any existing infestation. Vacuum shelves, corners, and baseboards to pick up crumbs, shed skins, and eggs.

In the scenario, the cardboard boxes were a major food source and hiding place. After emptying them, recycle or discard the boxes. Check behind appliances, under the sink, and along baseboards for cracks and gaps where silverfish hide. Seal these openings with caulk or weatherstripping. Decluttering the pantry and removing stacks of paper bags or old newspapers will reduce their shelter and make your repellent treatments more effective.

Step 3: Apply Targeted Repellents and Traps

Once the kitchen is drier and cleaner, use targeted products. Diatomaceous earth (food grade) is a fine powder that scratches the silverfish’s exoskeleton, causing them to dehydrate. Dust a thin layer along baseboards, under the sink, and in cabinet corners. Boric acid powder works similarly and is available at hardware stores; use it in cracks and crevices, but keep it away from food preparation areas and pets.

Sticky traps are useful for monitoring and catching silverfish. Place them flat against walls or under appliances where you’ve seen activity. In the scenario, you could place two or three traps in the pantry and near the sink. After a week, check the traps to see how many you’ve caught and where they are concentrated. This tells you if you need to reapply powder or move traps to new locations.

Product	How it works	Where to apply	Cautions
Diatomaceous earth	Dehydrates insects by damaging exoskeleton	Baseboards, cracks, under appliances	Use food grade; avoid inhaling dust
Boric acid powder	Toxic to silverfish when ingested	Cracks, crevices, behind cabinets	Keep away from food and pets
Sticky traps	Traps insects for monitoring and control	Along walls, under sink, in pantry	Check and replace weekly
Silica gel packets	Absorb moisture, reducing humidity	In cabinets and pantry	Keep away from children and food

Step 4: Monitor, Reapply, and Prevent Reinfestation

Silverfish eggs can hatch weeks after you treat adults, so persistence is key. After the first week, vacuum up the diatomaceous earth and reapply a fresh layer. Check the sticky traps and note where catches are highest. In the scenario, if you still see silverfish after two weeks, re-treat those hotspots and double-check for new moisture sources, such as a humidifier or a dripping refrigerator line.

Long-term prevention means keeping humidity low and food storage airtight. Continue running a dehumidifier during humid months, and repair any leaks promptly. Regularly inspect pantry items for signs of silverfish, such as small holes in packaging or yellow stains. By maintaining a dry, clean kitchen, you make it unlikely for silverfish to return.