5 Easy Ways to Get Rid of Silverfish Fast — And Make Sure They Don’t Come Back

Pests are never welcome in our homes, but there’s something particularly unsettling about silverfish. These small, wingless insects aren’t dangerous, but they’re kind of gross and can be destructive.

In an effort to figure out how to keep these critters at bay—or get rid of them if they’ve already invaded—we checked in with a few pros to find out their top tips.

What Are Silverfish?

According to entomologist Emma Grace Crumbley, silverfish are small, flat insects commonly found around the world, and range in size from around 1.5mm long up to 25mm long.

“They’re known for their flat bodies and three cerci—the tail-like appendages that protrude from the back of their abdomen,” Crumbley says.

They lack wings and are actually some of the oldest insects that still exist today, according to Crumbley… which only shows you just how persistent these little buggers are.

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Are Silverfish Dangerous?

Let’s start with the most important question first. Do these pests pose any threats to our health?

The good news is no—silverfish are not at all dangerous to humans. But as pest expert Ed Dolshun points out, they can still cause damage.

“They do pose a risk to your paper based items, such as cardboard, wall paper, and important documents,” says Dolshun.

Why You Have Silverfish

According to Dolshun, silverfish are attracted to damp, wet areas like humid bathrooms and damp basements. Crumbley agrees, noting that they also prefer darkness and stillness, which makes them most commonly found in any spaces that are cooler, hold moisture, and can go undisturbed for long stretches of time. 

“Folks don’t usually spot silverfish until the population’s grown,” Dolshun says. “If you spot them often, there may be a moisture or shelter problem somewhere in your home.”

How to Repel Silverfish

Get a Dehumidifier

According to Dolshun, your best first step is to invest in a dehumidifier. 

“This is essentially cutting off the main attraction for silverfish,” he says.

If silverfish are a constant, or big, problem, humidity levels are definitely something you need to monitor moving forward—especially in storage areas.

Remove Any Potential Food Sources

If you already have signs of an infestation, it might be time to declutter. You’ll need to tackle any books, papers, or cardboard boxes.

“Silverfish love cellulose-based materials,” Dolshun says. “If you’re storing things long term, skip the cardboard and go straight for the plastic bins.”

Try Sprinkling Diatomaceous Earth

After these two critical attractions are tackled, lay traps to rid yourself of any lurking silverfish. Dolshun recommends diatomaceous earth, a natural alternative to harsher insecticides that comes as a powdery substance that can be easily sprinkled in problem areas.

“Sprinkle it in cracks, behind appliances, or anywhere you’ve seen activity,” Dolshun says. “It’s non-toxic to people and pets but deadly to insects because it damages their exoskeletons and dehydrates them.”

However, DE should only be used once you’ve removed any excess moisture.

“When diatomaceous earth is wet, it doesn’t work as well,” he says.

Skip the Cedar

If you’ve heard that cedar blocks and sachets can repel silverfish, Dolshun disagrees. 

“This method attempts to hide the smell of cashmere and clothing from bugs,” he says. “This does not work on silverfish.”

Don’t Go Too Big

While store-bought sprays and chemicals might be effective, Dolshun says they’re often too heavy-handed for silverfish—at least at first.

“You have to take care of the damp environments, and cutting off potential food sources before any spray can be truly effective,” he says. “This will end up with them coming back.”

Prevent Future Infestations

Once you’ve cleared yourself of any existing silverfish—or even if you’re worried about one springing up in the future—Dolshun suggests taking steps to prevent their future friends from wandering in. 

“Sealing up gaps around baseboards, vents, and especially plumbing lines will be crucial here,” he says.