Silverfish and house centipedes are two of the most common nocturnal insects people spot in bathrooms, basements, and kitchens. They look nothing alike, but they share a love of damp, dark spaces, which is why you often find them in the same parts of your home. They also have a direct relationship: house centipedes hunt and eat silverfish. Understanding what each one does (and doesn’t do) helps you figure out whether you have a nuisance, a property problem, or a surprisingly helpful houseguest.
How to Tell Them Apart
Silverfish are small, teardrop-shaped insects covered in silvery scales. They’re typically half an inch to three-quarters of an inch long, with two long antennae at the front and three bristle-like tails at the rear. They move in a wriggling, fish-like motion, which is where they get their name. You’ll usually see them scurrying across a floor or countertop and freezing when a light comes on.
House centipedes look completely different. Their bodies are only about one to one and a half inches long, but with their 15 pairs of legs fanning out from the sides, they appear three to four inches in total length. The last pair of legs on adult females stretches to nearly twice the body length, giving them a dramatic, almost spidery silhouette. Their bodies are a dirty yellow with three dark longitudinal stripes, and their legs are banded in alternating light and dark segments. They’re extremely fast runners, which makes them startling to encounter despite being largely harmless.
House Centipedes Eat Silverfish
House centipedes are active predators. They hunt silverfish, spiders, cockroach nymphs, carpet beetle larvae, and other small household pests. If you’re seeing centipedes regularly, there’s a good chance they have a food supply nearby, and silverfish are one of their preferred meals. In this sense, centipedes act as a form of natural pest control. Killing every centipede you see can actually allow silverfish and other pest populations to grow unchecked.
That said, most people don’t want either insect running across the bathroom floor at 2 a.m. The practical takeaway: if you solve the conditions that attract silverfish, you’ll likely see fewer centipedes too, since their food source disappears.
Why Both Show Up in the Same Places
Moisture is the common thread. Both silverfish and house centipedes thrive in humid environments. Bathrooms, basements, laundry rooms, crawl spaces, and areas under kitchen sinks are prime territory. Leaky pipes, poor ventilation, and damp towels left in enclosed spaces all create the conditions these creatures need.
Both are nocturnal and avoid light, so you may have a sizable population without seeing more than the occasional straggler. They hide in cracks, behind baseboards, inside cardboard boxes, and under appliances during the day.
Silverfish Cause Property Damage
Of the two, silverfish are the ones that actually damage your belongings. They feed on starchy and protein-rich materials throughout your home:
- Books and documents: They eat binding glue, paper, and even ink, leaving irregular holes and scrape marks on covers.
- Photographs: The gelatin coating on printed photos is a particular favorite.
- Wallpaper: They consume the paste behind wallpaper, causing it to peel away from walls.
- Clothing and linens: Natural fibers like cotton, linen, and silk are vulnerable. You may notice small, irregular holes and yellow stains on fabrics.
- Pantry staples: Cereals, flour, and other dry goods can be contaminated. Silverfish leave droppings in food, which can also cause staining.
- Cardboard boxes: The starch in cardboard provides both food and shelter, making storage areas a hotspot.
Signs of a silverfish infestation include tiny pepper-like droppings, shed scales (which look like small, translucent flakes), yellow staining on paper or fabric, and irregular holes chewed through stored items.
House Centipedes Are Mostly Harmless
House centipedes do have venom, which they use to paralyze their insect prey. They can technically bite humans, but it’s uncommon. The small house centipede species found indoors delivers very little venom, comparable to a bee sting in terms of pain. You’d typically have to handle one or accidentally trap it against your skin to get bitten at all.
Redness, mild swelling, and pain at the bite site usually resolve within several hours to a few days. Serious reactions are extraordinarily rare. People with known allergies to bee or wasp stings face a slightly higher risk of an allergic response, but documented cases of severe complications from house centipede bites are nearly nonexistent. Between 1932 and today, only one to seven fatalities worldwide have been attributed to centipede bites of any species, and those involved much larger tropical varieties, not the house centipede.
House centipedes cause no property damage. They don’t eat paper, fabric, wood, or food. They don’t build nests or webs. Their only real downside is that they look alarming.
How to Reduce Both Populations
Since moisture drives both pests, controlling humidity is the single most effective step. Running a dehumidifier in basements, crawl spaces, and other chronically damp areas makes the environment far less hospitable. Keep bathrooms well-ventilated by opening a window or running an exhaust fan after showers, and don’t leave wet towels bunched up in enclosed spaces.
Fix any leaking pipes, dripping faucets, or condensation problems. These create the small pockets of dampness both insects depend on. Keeping rooms free of clutter, especially stacks of paper, cardboard boxes, and old magazines, removes both food sources for silverfish and hiding spots for centipedes.
Sealing entry points also helps. Caulk cracks along baseboards, around window frames, and where pipes enter walls. For persistent infestations, targeted crack-and-crevice treatments along baseboards and exterior barrier applications around foundations and window frames can cut off the pathways both insects use to get inside. A simple DIY trap for silverfish involves rolling up a damp newspaper, leaving it out overnight, and discarding it in the morning with the silverfish inside.
Which One Should You Worry About
If you’re only seeing the occasional house centipede, that’s generally not a problem worth solving aggressively. A few centipedes patrolling your basement are actively reducing other pest populations. If you’re seeing many centipedes, though, it signals a larger prey population (potentially silverfish) and a moisture issue worth addressing.
Silverfish are the bigger concern for most homeowners. A small number won’t cause noticeable damage, but populations grow slowly and steadily, and by the time you notice holes in stored clothing or peeling wallpaper, the infestation may be well-established. Addressing humidity and reducing starchy food sources early prevents the kind of gradual property damage that adds up over months and years.