Identification & Behavior
House Centipede — The Indoor Species
Scutigera coleoptrata is the centipede clients will call about. Adults reach 1–1½ inches in body length, but with their 15 pairs of extraordinarily long, banded legs they appear much larger — up to 3–4 inches across. Body color is yellowish-grey to tan with three dark dorsal stripes running lengthwise. Legs are banded in alternating light and dark. The last pair of legs (in females) are nearly twice the body length, easily mistaken for antennae. Two long antennae extend from the head. Movement is extremely fast — darting bursts of speed that startle most people.
Not to confuse with: Millipedes are slower, cylindrical (not flat), with two leg pairs per segment versus one, and do not bite. Stone centipedes (Lithobius spp.) are outdoor/soil dwellers, shorter and stockier — rarely found indoors.
Not to confuse with: Millipedes are slower, cylindrical (not flat), with two leg pairs per segment versus one, and do not bite. Stone centipedes (Lithobius spp.) are outdoor/soil dwellers, shorter and stockier — rarely found indoors.
Beneficial Status — Why They Matter
The house centipede is an active predator of common household pests. Its prey list includes cockroaches, silverfish, firebrats, carpet beetle larvae, flies, moths, spiders, termite swarmers, and bed bugs. They use venomous forcipules (modified front legs that deliver venom) to subdue prey — highly effective but essentially harmless to humans.
IPM framing: A centipede in the basement is evidence of other prey insects. Eliminating the centipede without addressing the prey population treats the symptom, not the cause. The Herbal Shield approach always explains this to clients: centipedes are a moisture and prey indicator, not a primary problem. Controlling their prey and moisture removes them naturally.
IPM framing: A centipede in the basement is evidence of other prey insects. Eliminating the centipede without addressing the prey population treats the symptom, not the cause. The Herbal Shield approach always explains this to clients: centipedes are a moisture and prey indicator, not a primary problem. Controlling their prey and moisture removes them naturally.
Bite Risk — Facts vs. Fear
Can they bite? Yes, but it is rare and requires deliberate provocation (picking one up, pressing against skin). Most reported "bites" are from the legs scratching skin, not a true venom injection.
Is it dangerous? No. The venom of Scutigera coleoptrata is not medically significant to healthy humans. The reaction resembles a minor bee sting — localized redness, brief pain, swelling that resolves within hours. No systemic toxicity has been documented. Note: individuals with bee sting allergies may have heightened sensitivity — advise clients to contact a physician if symptoms escalate beyond minor local irritation.
Jaw strength: Smaller centipedes often cannot pierce adult human skin at all. The jaws of Scutigera are weak relative to larger southern species.
Is it dangerous? No. The venom of Scutigera coleoptrata is not medically significant to healthy humans. The reaction resembles a minor bee sting — localized redness, brief pain, swelling that resolves within hours. No systemic toxicity has been documented. Note: individuals with bee sting allergies may have heightened sensitivity — advise clients to contact a physician if symptoms escalate beyond minor local irritation.
Jaw strength: Smaller centipedes often cannot pierce adult human skin at all. The jaws of Scutigera are weak relative to larger southern species.
Why Are They Here? — Root Causes
Centipedes require three things: moisture, prey, and harborage. They cannot survive in dry conditions — they breathe through spiracles and desiccate quickly without humidity. Finding centipedes indoors almost always points to:
1. Moisture problem — leaking pipes, high basement/crawl-space humidity, condensation, blocked gutters keeping foundation wet, window well moisture accumulation.
2. Prey population — an existing infestation of silverfish, cockroaches, flies, or other insects that sustains the centipede population.
3. Entry points — gaps at foundation, utility penetrations, basement window frames, crawl-space vents without screens.
Centipedes do not infest in the traditional sense — populations remain modest because they are territorial predators. Large numbers indicate a serious moisture or prey problem worth investigating.
1. Moisture problem — leaking pipes, high basement/crawl-space humidity, condensation, blocked gutters keeping foundation wet, window well moisture accumulation.
2. Prey population — an existing infestation of silverfish, cockroaches, flies, or other insects that sustains the centipede population.
3. Entry points — gaps at foundation, utility penetrations, basement window frames, crawl-space vents without screens.
Centipedes do not infest in the traditional sense — populations remain modest because they are territorial predators. Large numbers indicate a serious moisture or prey problem worth investigating.
Life Cycle & Seasonality in Maryland
Eggs: Females lay 35–150 eggs in soil or moist protected areas in spring and early summer. Some species guard eggs actively.
Juveniles: Hatch with 4 pairs of legs, adding segments and leg pairs with each molt. Development to adult takes 3 years.
Adults: Can live 5–7 years — unusually long for an arthropod. This means once established in ideal conditions, they persist long-term.
Maryland seasonality: Most visible indoors in fall as temperatures drop and centipedes seek warmth. Spring and summer activity peaks outdoors. Basement sightings are year-round in humid homes. Clients often report sudden increases in fall — this is normal seasonal movement, not a new infestation.
Juveniles: Hatch with 4 pairs of legs, adding segments and leg pairs with each molt. Development to adult takes 3 years.
Adults: Can live 5–7 years — unusually long for an arthropod. This means once established in ideal conditions, they persist long-term.
Maryland seasonality: Most visible indoors in fall as temperatures drop and centipedes seek warmth. Spring and summer activity peaks outdoors. Basement sightings are year-round in humid homes. Clients often report sudden increases in fall — this is normal seasonal movement, not a new infestation.
Where to Inspect — Priority Zones
Always inspect first: Basement and crawl space (especially near floor drains, sump pits, and along foundation walls), bathroom and kitchen plumbing cabinets, laundry room, window wells, utility/mechanical rooms with condensate drains.
Entry points: Foundation cracks and gaps, where plumbing enters through floors and walls, basement window frames, crawl-space vent screens (torn or missing), garage door thresholds.
Evidence: Centipedes are nocturnal — daytime sightings indicate high population density or a disturbed individual. Dead centipedes on sticky traps are useful monitoring evidence. Check sticky traps placed along basement baseboards and in floor drain areas.
Entry points: Foundation cracks and gaps, where plumbing enters through floors and walls, basement window frames, crawl-space vent screens (torn or missing), garage door thresholds.
Evidence: Centipedes are nocturnal — daytime sightings indicate high population density or a disturbed individual. Dead centipedes on sticky traps are useful monitoring evidence. Check sticky traps placed along basement baseboards and in floor drain areas.
IPM Action Steps
1
Moisture Assessment — The Root Fix
This is always Step One for centipedes. Inspect every potential moisture source in the affected areas. Use a moisture meter on basement walls and framing — readings above 19% in wood indicate conditions favoring both centipede harborage and structural decay. Check: plumbing supply and drain lines under sinks, around water heater and washing machine connections, basement/crawl-space relative humidity (target below 50%), condensate drain lines on HVAC systems, gutters and downspouts (confirm they drain away from foundation at least 6 feet), window well drainage. Document all findings for the client in writing. Moisture source elimination is the highest-value action you can take — it addresses centipedes, their prey, and often mold simultaneously.
2
Prey Identification & Treatment
Centipedes follow food. Identify what they are eating — inspect for silverfish (check closets, bookcases, attic), cockroaches (kitchen, bathroom, under appliances), flies (drains, trash areas, pet waste), or carpet beetle larvae (natural fiber storage areas). Treat the prey population using appropriate Herbal Shield protocols for each species. Reducing prey population is the single most effective centipede management step after moisture control. Explain this clearly to clients: "The centipedes are here because something else is here first. We address both."
3
Exclusion — Seal All Entry Routes
Centipedes enter through any gap wide enough to admit them — their flat body profile allows passage through surprisingly small openings. Seal with appropriate materials: hydraulic cement or masonry caulk for foundation cracks, copper mesh or foam backer rod + caulk for utility penetrations, steel wool packed tightly + caulk for larger gaps. Install or repair window well covers (polycarbonate dome styles prevent moisture accumulation and entry). Check crawl-space vent screens — torn or missing screens are a major entry route. Install door sweeps on basement exterior doors and weatherstripping on garage side doors. Note: complete exclusion of centipedes is difficult due to their body profile — moisture and prey control will always be more effective than sealing alone.
4
Humidity Reduction — Crawl Space & Basement
If basement or crawl-space relative humidity exceeds 60%, recommend mechanical humidity control. Options (recommend by severity): (1) Improve ventilation — ensure crawl-space vents are open and unobstructed; (2) Crawl-space vapor barrier — 6-mil poly sheeting covering all exposed soil dramatically reduces ground moisture evaporation; (3) Portable dehumidifier (client DIY) — adequate for moderately humid basements; (4) Whole-home dehumidifier with condensate drain — for chronically humid basements; (5) Crawl-space encapsulation — full sealed liner system for the worst cases. Centipedes cannot maintain population in well-ventilated, dehumidified spaces. This recommendation also protects against mold, wood rot, and dust mite problems — frame it as a whole-home health improvement, not just a bug fix.
5
Sticky Traps — Monitoring & Population Reduction
Place glue board traps along basement baseboards, in floor drain areas, laundry room corners, and under water heater. Centipedes move along walls and floor-wall junctions — position traps flat against baseboards. Check traps at 1 week and 2 weeks. High catch rates confirm active population and also capture their prey insects on the same trap, helping identify the food source. Replace traps every 4–6 weeks. Traps serve a dual purpose: monitoring effectiveness and physical population reduction. Do not place where children or pets can reach them.
6
Boric Acid & DE — Last-Resort Chemical Step
When exclusion and moisture control are underway but the client needs supplemental fast-acting treatment: apply boric acid dust into wall voids, crawl-space perimeter, under basement insulation batt edges, and around floor drain areas using a bellows duster. Apply food-grade diatomaceous earth in a thin layer along basement baseboards and crawl-space perimeter. Both work by physical desiccation — centipedes moving through treated areas absorb the dust through their cuticle and die of moisture loss within days. Neither poses residual chemical hazard to humans or pets when applied correctly in hidden areas. Cayenne pepper applied at exterior entry points (foundation vents, door thresholds) acts as a contact irritant that discourages entry — effective and fully safe. Do not use any pyrethroid sprays (bifenthrin, cypermethrin, lambda-cyhalothrin) — these are flagged by Beyond Pesticides for acute toxicity, chronic health effects, wildlife harm, and bee toxicity.
Prevention & Cultural Controls
Moisture & Humidity Reduction
Centipedes require humidity to survive — dehumidification is the single most effective long-term control. Target relative humidity below 50% in basements and crawl spaces. Fix all leaks, improve drainage, install vapor barriers, and ensure gutters direct water away from the foundation.
Eliminate Prey Insects
Centipedes follow their food source — silverfish, cockroaches, and other small invertebrates. Resolving underlying prey infestations removes the centipede's reason to be indoors. Address any known moisture-loving pest issues concurrently with centipede treatment.
Structural Exclusion
Seal all foundation cracks, pipe penetrations, and basement window gaps with hydraulic cement or silicone caulk. Install tight door sweeps on all ground-level and basement doors. Centipedes can enter through very small openings — a 1/4-inch gap is sufficient. Install fine mesh on basement vents.
Application Techniques
🌡️ Moisture Metering — Baseline Documentation
- Use a pin-type moisture meter on any exposed wood in basement/crawl space (joists, sill plates, subfloor). Record readings at each location.
- 19–28% moisture = elevated risk — recommend repair; over 28% = active moisture damage, immediate repair advised.
- Use a hygrometer or RH sensor to document ambient relative humidity in basement/crawl space at time of visit.
- Photograph all moisture sources — leaks, efflorescence on concrete walls, rust staining, wood discoloration — and include in the client report.
- Document in writing: "Centipede activity correlates with RH of [X]% — reducing to below 50% is the primary treatment objective."
- Follow up at 30 days with a re-meter — this demonstrates value and identifies persistent moisture sources.
💨 Boric Acid Dust — Wall Void & Crawl Space Application
- PPE: N95 respirator, gloves, safety glasses. Boric acid is low toxicity but irritating to airways and eyes at high concentration.
- Use a bellows hand duster. Fill to 1/3 capacity — overfilling prevents proper dust dispersal.
- Inject into wall voids via outlet plate gaps, small drilled holes (reseal after), or existing gaps at pipe penetrations.
- Apply a thin dusting along crawl-space perimeter walls and around floor drain perimeters — do not over-apply. A light, barely-visible coating is correct; visible piles are wasteful and unnecessary.
- Keep children and pets out of treated areas until dust settles completely (30+ minutes).
- Document all treatment locations on the service report for follow-up reference.
⚗️ Diatomaceous Earth — Perimeter Barrier
- Use food-grade DE only. Non-food-grade (pool filter) DE has a different crystalline structure that is harmful to lungs — never use it indoors.
- Apply with a duster or puffer bottle along basement baseboards and crawl-space perimeter.
- Keep the layer thin and undisturbed — a thick visible ridge is unnecessary and gets kicked up as airborne dust. A light dusting is fully effective.
- DE loses effectiveness when wet — do not apply in areas with standing water or heavy condensation until the moisture issue is repaired.
- Reapply after vacuuming or in areas that become wet.
- Effective against centipedes, silverfish, carpet beetle larvae, and cockroach nymphs that travel through the barrier.
🌶️ Cayenne Pepper — Entry Point Deterrent
- Apply dried cayenne pepper powder (standard grocery store spice) at exterior foundation vent openings, basement window frame gaps, and door threshold gaps where centipedes are observed entering.
- Capsaicin irritates centipede sensory organs — they avoid treated surfaces.
- Reapply after rain or when the powder is washed or blown away.
- Keep away from areas where clients or pets may contact it directly — causes irritation to eyes and mucous membranes.
- Explain to clients this is a temporary deterrent supplement, not a standalone solution. Seal gaps permanently after applying as a bridge measure.
- Fully safe — GRAS (Generally Recognized As Safe) food ingredient. No chemical residue concerns whatsoever.
🪤 Sticky Trap Placement — Monitoring Protocol
- Place glue boards flat against basement baseboards — centipedes run along wall-floor junctions. Do not stand traps up.
- Place one trap near each floor drain, sump pit opening (outside the pit), and laundry drain area.
- Place additional traps in bathroom cabinet bases and under water heater (if accessible).
- Record placement locations and date on each trap with a marker.
- Check at 7 days — count and photograph catch. High counts at specific traps indicate active harborage areas nearby.
- Note prey species captured alongside centipedes — this identifies the food source species for targeted treatment.
- Replace every 4–6 weeks or sooner if loaded.
Recommended Products
💨
Harris Boric Acid Powder
Applied with bellows duster into wall voids, crawl-space perimeter, and around floor drains. Works by physical desiccation — kills centipedes and their prey (silverfish, cockroaches) as they move through treated areas. Precision-tip applicator included. Excellent residual — remains effective as long as it stays dry. Low mammalian toxicity; safe in hidden crevices away from food contact surfaces.
Boric Acid / Desiccant
⚗️
Harris Food-Grade Diatomaceous Earth
Mechanical kill agent applied along basement baseboards and crawl-space perimeter. Food-grade (amorphous silica) — safe for use around pets and in areas near food storage when applied correctly. Effective against centipedes and their common prey: silverfish, cockroaches, carpet beetle larvae. Loses efficacy when wet; reapply after moisture events. Multi-pest control value makes this a standard part of any moisture-pest treatment.
Food-Grade DE / Mechanical
🪤
Catchmaster Multi-Insect Glue Boards
Wide-format sticky traps for monitoring centipede activity along basement floor-wall junctions and near drains. Captures centipedes and prey insects simultaneously — invaluable for identifying what centipedes are eating in a specific home. Non-toxic, no chemicals. Position flat against baseboards. 30-day effective period. Essential for pre-treatment baseline documentation and post-treatment follow-up comparison.
Monitoring / Non-Toxic
🌶️
Cayenne Pepper (Bulk Spice)
Applied at exterior entry points — foundation vent gaps, basement window frames, door thresholds — as a contact irritant deterrent. Capsaicin disrupts centipede chemoreception and discourages entry. Fully food-safe, zero chemical residue concerns, economical. Reapply after rain. Works best as a bridge measure while permanent exclusion sealing is completed. Also effective against other crawling arthropods using the same entry routes.
Botanical / Entry Deterrent
🌡️
Moisture Meter + Hygrometer
Pin-type moisture meter for reading wood moisture content in basement framing. Digital hygrometer for ambient relative humidity. Both are essential diagnostic tools — not optional for centipede accounts. Findings documented in the service report establish why centipedes are present and give the client measurable targets for follow-up (RH below 50%, wood moisture below 19%). Positions Herbal Shield as a thorough, science-based service vs. spray-and-pray competitors.
Diagnostic Equipment
🛡️
Crawl Space Vapor Barrier (6-mil Poly)
Recommend to clients as a DIY or contractor installation for crawl spaces with exposed soil. Covering exposed soil with 6-mil polyethylene sheeting — overlapping seams by 12 inches and extending up foundation walls — reduces ground moisture evaporation by 80–95%. This single measure often eliminates chronic moisture pest problems (centipedes, silverfish, subterranean termite risk) without any chemical treatment. Offer as an add-on service or referral to a trusted contractor partner. Delivers lasting results that chemical treatments alone never achieve.
Structural Prevention
Training Videos
Reading Moisture — The Centipede Baseline Inspection
How to use a pin moisture meter and hygrometer in a basement and crawl space. What readings indicate centipede-favorable conditions. How to document findings and present a moisture reduction recommendation to clients in plain language.
Coming Soon
Centipede vs. Millipede — Field ID & Client Education
How to confidently tell house centipedes apart from millipedes and other multi-legged arthropods. The client communication script for explaining beneficial status — turning a "I'm terrified" call into a trusted education moment about your IPM approach.
Coming Soon
Crawl Space Moisture Protocol — Inspection to Recommendation
Full walkthrough of a crawl-space inspection for moisture pest accounts. How to identify vapor barrier condition, ventilation issues, and standing water. When to recommend a vapor barrier vs. dehumidifier vs. full encapsulation — and how to upsell it appropriately.
Coming Soon
Boric Acid & DE Dust Application — Crawl Space & Wall Voids
Proper bellows duster loading and technique for wall void injection and crawl-space perimeter treatment. Common application mistakes (over-dusting, wrong locations). PPE requirements and post-application client instructions for centipede and moisture pest accounts.
Coming Soon
Warnings & Herbal Shield Standards
Client Script — Reframe the Centipede: "I know they look alarming, but house centipedes are actually one of the most helpful things living in your basement. They eat cockroaches, silverfish, and other pests. What I want to do today is find out why they're thriving here — it almost always comes back to moisture. If we fix the moisture and the other insects that are feeding them, the centipedes move on naturally. You'll probably see fewer of every pest in this area, not just the centipede."
Never Recommend Pyrethroid Sprays for Centipedes: Bifenthrin, cypermethrin, lambda-cyhalothrin, deltamethrin, and PBO-containing products are flagged by Beyond Pesticides for acute health effects, chronic toxicity, bee toxicity, and wildlife harm. They are not approved Herbal Shield products. Broadcast spraying for centipedes also eliminates the beneficial predator role they play while leaving the prey population (and the moisture that sustains it) entirely untouched — guaranteeing re-infestation. Clients who demand a spray should be educated that the spray does not fix the problem; it only hides it temporarily.
Bite Response Guidance for Clients: If a client is bitten, advise: wash the area with soap and water, apply a cold pack for 10 minutes, and take an over-the-counter antihistamine (like diphenhydramine) if itching or swelling is uncomfortable. The reaction is equivalent to a minor bee sting and resolves in a few hours. Clients with known hymenoptera (bee/wasp) venom allergies should consult their physician before dismissing any unusual reaction. No systemic toxicity has been documented from Scutigera coleoptrata bites — this is a factual point worth communicating clearly to reduce client alarm.
PPE for Crawl Space Work: Any crawl-space inspection or treatment requires: N95 minimum (P100 preferred) respirator, disposable coverall or washable work clothes dedicated to crawl-space use, gloves, safety glasses, and a headlamp. Crawl spaces may contain mold, rodent droppings, asbestos insulation (older homes), and insect frass. Never enter a crawl space without proper respiratory protection — this applies to every visit, not just treatment days.