House centipedes, also known as Scutigera coleoptrata, are common arthropods that live in damp areas inside homes. While some homeowners consider them pests, house centipedes are actually beneficial because they prey on other insects. Still, seeing multiple house centipedes at once can be alarming. So how many of these leggy creatures is normal to have in your home?
What Are House Centipedes?
House centipedes are yellowish-grey insects with long, flattened bodies made up of 15 to 177 segments. Each segment has a pair of legs attached to it, so house centipedes have between 30 and 354 legs in total. The legs are banded light and dark and allow the centipede to move very quickly, up to 1.3 feet per second.
At the end of the body are a pair of tail-like appendages called cerci. House centipedes use these pincer-like cerci to capture prey. They also have two very long antennae and two compound eyes. Adult house centipedes range from 1 to 1 1⁄2 inches in length.
Where Are House Centipedes Found?
As their name suggests, house centipedes live inside homes, specifically in areas with high humidity. They like bathrooms, basements, closets, garages, attics, and crawl spaces. They enter homes through cracks in the foundation or small openings around windows, doors, pipes, vents, and wires.
House centipedes originate from the Mediterranean region but are now found worldwide in many temperate climates. They are common in the United States, Canada, Mexico, Central America, South America, Europe, North Africa, and Asia.
Why Are House Centipedes Beneficial?
House centipedes prey on many household pests like cockroaches, flies, moths, bed bugs, silverfish, earwigs, and spiders. They help control these populations, which means fewer bothersome bugs in your home. House centipedes typically only eat insects and other arthropods and do not bother humans or pets.
So while their appearance can be startling, house centipedes are harmless to humans and provide a free pest control service. Many entomologists recommend tolerating their presence as they are more helpful than harmful.
Typical House Centipede Population
The number of house centipedes living in a home will depend on factors like:
- Climate – warmer, humid regions see more centipedes
- Home age – older homes provide more entry points
- Sanitation – cleaner homes have less food for centipedes
- Pest control – treatment reduces insect populations centipedes eat
In general, 5-10 house centipedes is common in an average home at any given time. Seeing 1-2 per day is normal, especially in spring and summer when breeding occurs. Sudden large increases may indicate a pest problem that is attracting more centipedes as prey.
Here is a breakdown of what to expect:
Northern Climates
In cooler, drier regions of the northern U.S., Canada, and Europe, house centipede populations tend to be lower. Homes here may have:
- 2-5 individuals at one time
- 1-2 seen per day on average
- 5-10 per season
Southern Climates
Warmer, more humid southern regions of the U.S., Mexico, South America, Southern Europe, and Asia provide ideal house centipede habitat. Homes here may have:
- 5-15 individuals at one time
- 2-3 seen per day on average
- 10-25+ per season
Coastal Regions
Homes along coasts tend to be more humid and attract more house centipedes. Populations may be:
- 10-25 individuals at once
- 3-5 seen daily
- 25-50+ per season
Signs of a House Centipede Infestation
While the averages listed above are normal, constantly seeing 10+ house centipedes daily or 100+ per season likely indicates an infestation. Signs your home may have too many house centipedes include:
- Seeing groups of 10+ centipedes at once
- Noticing them during the day in open areas
- Finding them in upper floors or rooms far from soil
- Seeing more each day for weeks
- Encountering over 100 per season
An infestation suggests there is an extremely large insect population in the home, providing the centipedes with abundant food. It also means females have plenty of resources to continue breeding.
Factors That Increase House Centipedes
Certain conditions can cause house centipede populations in a home to grow and reach infestation levels:
Accessible Harborage Sites
An old home with many cracks, crevices, gaps around utilities, unfinished basements or crawlspaces, and clutter provide ideal harborage sites for centipedes to hide and breed. Sealing these areas reduces the population capacity.
Moisture and Humidity
Centipedes thrive in damp areas and need humidity around 75-90%. Leaky pipes, poor ventilation, overwatering plants, wet basements and soil under homes raise moisture levels. Controlling humidity and fixing leaks helps limit centipedes.
Prey Availability
A home infested with other insects gives centipedes plenty of food. A cockroach or silverfish infestation, for example, allows the centipede population to boom. Getting rid of other pests first reduces the resources for centipedes.
Time Outdoors
Spending time outdoors gives centipedes more opportunities to enter the home. Items like firewood and potted plants brought indoors also transport centipedes. Limiting these exposures helps prevent entry.
Poor Sanitation
Dirty homes with food scraps and clutter attract household pests that centipedes prey on. Improved cleaning and sanitation leaves less food sources and limits centipede populations.
Getting Rid of Excess House Centipedes
If the number of house centipedes becomes a problem, there are several ways to control populations:
Reduce Moisture
Install dehumidifiers in damp basements or crawlspaces to maintain humidity under 50%. Ensure air conditioning units drain properly. Fix any leaks and use fans to dry out moist closets or rooms.
Seal Entry Points
Caulk and weatherstrip around windows and doors. Seal openings around pipes and wires with copper mesh, steel wool, or other materials. This blocks access from outside.
Limit Outdoor Transfers
Keep firewood, plants, and other outdoor items away from the home’s exterior to prevent centipedes from catching a ride inside. Check items already inside carefully before moving.
Clean and Declutter
A clean home leaves little food waste and hiding spots for centipede prey. Vacuum and mop floors, clean countertops, empty trash regularly, and reduce clutter to discourage populations.
Use Dehumidifiers and Fans
Run dehumidifiers and fans to maintain dry air.Dirting closets, basements and attics helps make the environment less welcoming.
Remove Leaf Litter and Debris
Rake leaves, trim vegetation, and clear any wood or compost piles touching the home’s exterior walls. This eliminates moist hiding spots close to entry points.
Change Landscaping
Replace dense, wet mulch areas near the home’s foundation with gravel, rocks, or bark to reduce moisture and appeal. Pull back edging and trim plants to expose centipede hiding spots.
Apply Insecticides
Insecticide sprays or dusts applied along baseboards, windows, doorways, attic vents, and other entry points can help reduce populations entering from outside. Follow product instructions carefully.
Use Traps
Glue board traps or pheromone traps catch centipedes lured in. Place traps along walls and in secluded spots where centipedes travel. Check traps frequently to dispose of captured centipedes.
Bring in Natural Predators
Certain animals like frogs, geckos, spiders, and house wrens prey on centipedes. Introducing them to an indoor or outdoor environment can provide natural population control.
Professional Pest Control
For severe house centipede infestations, professional pest control may be needed. An exterminator can:
- Inspect inside and outside to find entry points
- Seal cracks, gaps, and other access points
- Apply targeted insecticides in strategic locations
- Install monitoring traps and recommend ways to make the home less hospitable
- Follow up to ensure centipedes are eliminated
Treatment plans usually involve at least two initial visits, then follow-ups until the centipede problem is resolved. Expect to pay $200-$400 depending on the size of your home.
Prevent House Centipede Infestations
Prevention is the best long-term approach for controlling house centipedes:
- Install door sweeps, weatherstripping, screens, and caulk to seal exterior entry points
- Keep basements and crawlspaces dry with dehumidifiers and fans
- Avoid stacking wood against outside walls
- Clear leaves, mulch, and debris near the foundation
- Follow sanitation practices like cleaning frequently, drying damp areas, and taking out trash
- Fix leaky plumbing promptly
- Limit indoor plants and check outdoor items for centipedes before bringing them inside
- Treat other household pests to limit centipede food supply
Following proactive prevention tips eliminates conditions that allow centipede populations to thrive. This minimizes the need for control measures later.
Conclusion
Seeing a house centipede now and then is normal, especially in spring and summer. While startling, these creepy-looking arthropods are harmless and actually help curb other insect pests. Most homes have 2-15 present at a time. But consistent sightings of 10+ daily or 100+ annually likely indicates a substantial infestation requiring control measures. Reducing moisture, sealing entry points, cleaning thoroughly, and employing traps or insecticides can help eliminate excessive house centipedes. Prevention tactics also keep populations low long-term. With vigilance, these annoying but beneficial creatures can be kept to a reasonable number.