Silverfish vs. Centipedes: Key Differences and How to Identify Each

Silverfish and house centipedes are two of the most common moisture-loving pests found in homes. Both prefer dark, damp environments and are often spotted in the same locations — basements, bathrooms, and kitchens. Despite sharing habitats, these are fundamentally different creatures with very different roles in your home ecosystem. Here is how to tell them apart and what each means for your household.

Appearance Comparison

Silverfish

• Body type: Insect (six legs)
• Shape: Teardrop-shaped, wider at the head, tapering to the rear
• Size: 12–19 mm body length
• Color: Silvery-gray with metallic scales
• Legs: Six short legs
• Antennae: Long, thin antennae
• Tail: Three long bristle-like filaments
• Movement: Rapid, fish-like wriggling

House Centipedes

• Body type: Myriapod (many legs) — not technically an insect
• Shape: Long, segmented, and flattened
• Size: 25–50 mm body length (often appears much larger due to long legs)
• Color: Yellowish to grayish-brown with darker stripes
• Legs: 15 pairs (30 legs total) of extremely long, banded legs
• Antennae: Very long, prominently segmented antennae
• Tail: The last pair of legs extends rearward and can resemble a second set of antennae
• Movement: Extremely fast, darting runs — one of the fastest arthropods relative to body size

The number of legs is the most obvious difference. If it has many long legs radiating from a segmented body, it is a centipede. If it has six legs and a smooth, scale-covered teardrop body, it is a silverfish.

The Predator-Prey Relationship

Here is an important fact that surprises many homeowners: house centipedes eat silverfish. Centipedes are generalist predators that feed on many household pests, including silverfish, cockroaches, spiders, ants, and bed bugs.

This means that finding both centipedes and silverfish in your home is not a coincidence — the centipedes are there because the silverfish (and other prey) are there. In a sense, centipedes are providing free pest control.

Should You Kill Centipedes?

This is a personal decision. House centipedes are beneficial predators that help control silverfish and other pest populations. However, many people find their appearance alarming, and their fast movement can be startling. From a pest control perspective, centipedes are helpful — but if their presence bothers you, addressing the conditions that attract both them and their prey (humidity and other pests) is the best approach.

Habitat Preferences

Both silverfish and centipedes prefer damp, dark environments, which is why they are often found in the same rooms.

Silverfish prefer:

• Bathrooms
• Basements
• Closets
• Behind and under appliances
• Inside stored items

Centipedes prefer:

• Basements and crawl spaces
• Bathrooms
• Dark corners and spaces behind furniture
• Drain areas
• Any space with an active prey population

Diet Comparison

Silverfish are scavengers that feed on paper, books, clothing, starches, sugars, and pantry foods. They cause property damage but pose no direct threat to people.

Centipedes are active predators. They feed on:

• Silverfish
• Cockroaches
• Spiders
• Ants
• Flies
• Bed bugs
• Other small arthropods

Centipedes use venomous fangs to subdue their prey. Their venom is effective against insects but is generally harmless to humans — a centipede bite may cause mild, localized pain similar to a bee sting, but is not medically significant for most people.

Do They Bite?

Silverfish do not bite and cannot harm humans.

Centipedes can bite if handled or trapped against skin, but they rarely do so. Bites cause temporary pain and mild swelling but are not dangerous to healthy adults. Allergic reactions are rare.

Damage Potential

Silverfish cause significant damage to stored materials — books, papers, clothing, wallpaper, and food. This is the main reason they are considered pests.

Centipedes do not cause property damage. They do not feed on household materials, nest in walls, or create structural issues. Their only "damage" is the psychological distress their appearance causes some homeowners.

Control Approaches

For Silverfish

Follow a comprehensive control plan that includes:

• Humidity reduction
• Sealing entry points
• Diatomaceous earth and boric acid
• Traps
• Food source removal

For Centipedes

The best way to reduce centipede populations is to reduce their food supply — which means controlling silverfish and other pests. Additionally:

• Reduce humidity with dehumidifiers
• Seal cracks and gaps
• Remove outdoor debris near the foundation
• Use sticky traps to monitor populations

Addressing Both

Since centipedes are in your home because prey insects like silverfish are present, the most effective strategy is to address the underlying silverfish infestation. As the silverfish population declines, centipede numbers will follow.

For a complete silverfish removal plan, visit our guide on how to get rid of silverfish and the complete guide to silverfish.

Expert Insight

"I get asked about the difference between silverfish and house centipedes all the time," says Sarah Mitchell, BCE. "In my 15 years of IPM experience, I have found that homes with silverfish often have house centipedes too — because centipedes prey on silverfish. If you are seeing both, the centipedes are actually providing some natural control, but the underlying moisture issue needs to be addressed regardless."

Main Causes

Both silverfish and house centipedes are present in homes because of the same root condition: elevated indoor humidity combined with dark, undisturbed spaces that provide shelter. Silverfish are attracted to the combination of moisture above 50 percent relative humidity and starchy food sources including paper, fabric, and dry goods. House centipedes are attracted to homes with established silverfish and other prey insect populations -- they follow the food supply rather than arriving independently. Any home with a consistent moisture source, such as a leaking pipe, poor bathroom ventilation, or an unfinished basement with chronically high humidity, creates the conditions that sustain silverfish populations and in turn draw centipedes to the same spaces as opportunistic predators.

Prevention

Preventing both silverfish and centipedes requires addressing the shared root condition: indoor humidity. Keep relative humidity below 50 percent throughout the home, with particular attention to basements, bathrooms, and crawl spaces. Fix plumbing leaks, install or upgrade bathroom exhaust fans, and run a dehumidifier in persistently damp areas. Seal cracks and gaps in baseboards, foundation walls, and pipe penetrations to limit entry routes for both species. Remove outdoor harborage -- leaf litter, wood piles, and debris near the foundation -- that shelters both pests before they enter. As the silverfish population declines through environmental control, centipede numbers will decline proportionally since their food supply has been reduced. Ongoing monitoring with sticky traps tracks both populations simultaneously.

How to Identify

Confirm silverfish through direct observation in the early morning, by inspecting under sinks, behind toilets, in basements, around hot water heaters, and inside seldom-opened storage. They are flat, teardrop-shaped, silver-gray, ten to twelve millimeters long, with three tail filaments and rapid darting movement when exposed to light. Cast skins along baseboards and inside cardboard storage are common evidence. Damage to wallpaper edges, book bindings, photo albums, stored documents, and dried pantry items follows characteristic patterns — irregular surface etching and notched edges rather than holes. Sticky traps placed in corners of bathrooms, basements, and storage areas catch active adults overnight and confirm the active rooms.

Risk and Severity

Silverfish pose no direct medical threat — they do not bite, sting, transmit disease, or contaminate food in ways that produce illness. The risk is material damage. They feed on book bindings, paper documents, photographs, wallpaper paste, fabric starch, cardboard, and stored dry goods, causing irreversible damage to archived materials, family photographs, important documents, library books, and stored clothing. Heavy populations also indicate persistent moisture problems that drive secondary issues — mold growth, structural wood decay, and other moisture-loving pests like booklice and mold mites. Allergic sensitivity to silverfish scales has been documented in a small number of cases. Risk scales with the value of stored paper goods and the severity of underlying humidity issues.

Solutions and Actions

Silverfish respond to a combined moisture-control and targeted-treatment program. Address the underlying humidity problem first by running a dehumidifier in basements and storage areas to keep relative humidity below fifty percent, repairing slow leaks, improving bathroom ventilation, and resolving condensation on cold-water pipes. Apply diatomaceous earth or boric acid dust in cracks and crevices, behind baseboards, under bath fixtures, and around utility penetrations — these slow-acting desiccants work as silverfish move through treated areas. Place sticky monitor traps in active rooms to verify the population is declining. Inspect cardboard storage, dispose of damaged boxes, and switch to plastic storage bins for paper goods, books, and clothing. Treatment without humidity control consistently fails.

Frequently Asked Questions

Can house centipedes help control silverfish?

Yes. House centipedes are predators that feed on silverfish, among other small insects. If you see both house centipedes and silverfish, the centipedes are providing some natural pest control. However, both pests indicate a moisture problem that should be addressed — eliminating the excess humidity will reduce populations of both.

How can I tell a silverfish from a centipede?

Silverfish have a teardrop-shaped body with three tail filaments and six legs. House centipedes have a long, flat, segmented body with 15 pairs of legs and move extremely fast. Silverfish have a metallic silver color, while house centipedes are yellowish-brown with dark stripes on their legs.

Should I kill house centipedes if I have silverfish?

It is generally not recommended to eliminate house centipedes if you have silverfish, as centipedes provide natural predatory control. Instead, focus on reducing humidity to address both pests simultaneously. Once humidity drops below 50 percent, both silverfish and house centipede populations will decline.

What should I check after noticing centipedes silverfish activity?

After noticing centipedes silverfish activity, inspect the nearest dark cracks, baseboards, pipe openings, stored paper, and humid corners. Use a flashlight at night and place sticky traps along the route where the insect disappeared. That pattern tells you whether the issue is a single wanderer or a supported harborage with moisture and food sources that need correction.

Sources and Further Reading

• NPMA — Silverfish Overview
• Purdue Extension — Silverfish Control
• NC State Extension — Silverfish and Firebrats
• Penn State Extension — Silverfish Fact Sheet