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Woodlouse Spider (Woodlouse Hunter)

Woodlouse Spiders in Collin County, TX | Identification and Control

Last updated 2026

The woodlouse spider is a red-orange spider with disproportionately large fangs found under flagstones, patio pavers, and flower pots across Collin County. It is one of the most alarming-looking spiders homeowners encounter during yard work, and one of the least medically dangerous. Its primary prey is pill bugs and sowbugs. Getting rid of it starts with understanding the pill bug problem first.

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Woodlouse spider showing vivid reddish-orange cephalothorax, pale abdomen, and forward-projecting oversized chelicerae on patio flagstone
Woodlouse spider specimen showing reddish-orange cephalothorax, pale abdomen, and oversized forward-projecting chelicerae
Woodlouse Spider
Dysdera crocata
AKA Woodlouse Hunter · Pill Bug Spider · Sowbug Spider
Risk AssessmentTap each axis to jump to detail
People 1 / 3
Bite extremely rare; verified bites produce minor localized redness only; no necrosis, no systemic effect; medical significance is LOW
Property 1 / 3
No structural damage; outdoor species that does not establish indoor colonies; shelter is under hardscape, not inside the structure
Persistence 2 / 3
Directly tied to pill bug population; recolonizes within weeks if prey base is not reduced; spring and fall call peaks consistent year over year
Difficulty to Treat 2 / 3
Requires pill bug control and shelter reduction; surface spray alone fails; retreats hidden under hardscape are not reached by standard perimeter spray
1 Low 2 Moderate 3 High
Body lengthFemale 0.43 to 0.59 in (11-15 mm); male 0.35 to 0.39 in (9-10 mm)
ColorVivid reddish-orange cephalothorax and legs; pale cream to grayish-yellow abdomen
Eye arrangementSix eyes in a tight oval cluster; different from brown recluse’s three separated pairs
Hunting styleNocturnal hunter; no prey-capture web; silk tube retreat under hardscape
Primary preyPill bugs and sowbugs; also silverfish, earwigs, small beetles, and crickets
Active seasonYear-round in North Texas; peak call season April-May and September-October
Threat levelLOW

A red-orange spider with oversized fangs that looks scary, lives under your flagstone, and exists mainly to eat your pill bugs. Woodlouse spider identification and facts confirm this species as one of the least medically dangerous spiders homeowners encounter despite its alarming appearance.

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North Texas Pest Calendar
Woodlouse Spider Activity in Collin County by Month

Woodlouse spiders are present year-round in Collin County but call volume peaks in spring (April-May) and fall (September-October) when homeowners are most active in their yards. The spider is not necessarily more active in those months: encounters spike because digging in mulch beds, lifting flagstones, and moving flower pots for seasonal plantings exposes the spider’s daytime retreat. North Texas mild winters allow woodlouse spiders to remain active at low levels through January and February, with activity increasing as soil temperatures rise through March.

Jan
Low
Feb
Low
Mar
Emerging
Apr
Peak
May
Peak
Jun
Active
Jul
Active
Aug
Active
Sep
Peak
Oct
Peak
Nov
Active
Dec
Low
Dormant / Low
Emerging
Active
Peak (call season)

Pattern from iNaturalist observation records and Pest Me Off service call data across Collin County, 2023 to 2026.

Identification

What a Woodlouse Spider Looks Like

Red-orange in front, pale in back, huge fangs, six eyes in an oval cluster – nothing in Collin County that is actually dangerous looks like this

The woodlouse spider (Dysdera crocata) is one of the most visually distinctive spiders in North Texas. The cephalothorax (front body section) and all eight legs are vivid reddish-orange, often described as tawny, rust-colored, or orange-red. The abdomen is pale: cream to grayish-yellow to light beige. This two-tone color pattern is unique among Texas spiders. No other common Collin County spider has this combination of reddish-orange front and pale abdomen.

The chelicerae (the fang-bearing structures at the front of the spider’s face) are the second major diagnostic feature and the primary source of homeowner alarm. They are disproportionately large for the spider’s body size, projecting forward and slightly outward so they are clearly visible without magnification. The spider raises and spreads them when threatened, which produces an intimidating display. The oversized chelicerae are an evolutionary adaptation for piercing the calcified exoskeleton of pill bugs, not for threatening humans. Adult females reach 0.43 to 0.59 inch in body length; males run slightly smaller at 0.35 to 0.39 inch. The body is stocky and not flattened.

Woodlouse spider identification diagram showing reddish-orange cephalothorax, pale abdomen, oversized chelicerae, and six-eye oval cluster

Woodlouse spider identification: reddish-orange cephalothorax, pale abdomen, oversized chelicerae, six-eye oval cluster

Dead GiveawaysWhat makes the woodlouse spider unmistakable
  • Vivid reddish-orange or rust-colored cephalothorax and legs; pale cream to beige abdomen
  • Oversized chelicerae (fangs) clearly visible from the front without magnification
  • Six eyes in a tight compact oval cluster (brown recluse has six eyes in three separated pairs)
  • Stocky, not-flattened body; compact build compared to cellar spider or brown recluse
  • Found by lifting flagstone, paver, or flower pot – not in webs on walls or in closets
  • Small silken tube retreat visible inside the gap under the stone where it was found
  • No prey-capture web present near the spider
  • Usually found near heavy pill bug populations in mulch beds and under pavers
The Name

Why It Is Called the Woodlouse Spider

The woodlouse is the British common name for what most American homeowners call a pill bug or roly-poly: the armored crustacean (Armadillidium vulgare and related Porcellio species) that rolls into a ball when touched and lives in moist soil and mulch. The woodlouse spider is named for its primary prey. Dysdera crocata is a specialist predator whose oversized chelicerae are specifically adapted for piercing the hard calcified shell of these small crustaceans. One fang strikes from above and the other from below in a coordinated pincer motion, cracking a defensive layer that defeats most other spider species entirely.

The species originated around the Mediterranean basin and spread worldwide over centuries of trade as a stowaway in soil and potted plants. It is now established across much of the eastern and central United States, including confirmed presence in Texas and across the DFW region. Woodlouse hunter spider biology and identification covers the chelicerae mechanics and prey capture behavior in more detail.

Look-Alikes

How to Tell Woodlouse Spiders from Other Collin County Spiders

The woodlouse spider is frequently misidentified as brown recluse because of its large chelicerae and the context in which it is found: a medium-sized spider under a stone or in the yard. The color difference eliminates the brown recluse immediately for anyone who can see the spider clearly, but poor lighting under a paver or a brief startling encounter can cause homeowners to miss the diagnostic color features.

Species Size Key Feature Where Found
Woodlouse Spider
Woodlouse Spider AKA: Woodlouse Hunter, Pill Bug Spider Dysdera crocata This species
0.43 to 0.59 in body (female); stocky, not flattened. Legs are stout and reddish-orange matching the cephalothorax. Vivid reddish-orange cephalothorax and legs. Pale cream to beige abdomen. Oversized chelicerae projecting forward, visible without magnification. Six eyes in tight oval cluster. No prey-capture web. Found under hardscape, not in corners or indoor storage. Under flagstones, patio pavers, landscape rocks, potted plant saucers, mulch beds. Outdoor species. Rarely indoors except as a wanderer through garage or patio doors.
Brown Recluse
Brown Recluse AKA: Violin Spider, Fiddleback Loxosceles reclusa
0.25 to 0.5 in body; leg span 1 to 1.5 in. Slender, lightly built, flat-bodied. Uniformly matte tan to medium brown; no reddish or orange coloration anywhere. Uniformly matte tan to brown body throughout. No reddish-orange coloration. Six eyes in THREE DISTINCT SEPARATED PAIRS in a semicircle (not an oval cluster). Violin-shaped marking on cephalothorax. Standard-sized chelicerae (not oversized). MEDICALLY SIGNIFICANT. Dark undisturbed indoor spaces: closets, stored boxes, rarely-moved furniture, garage shelving. Not under flagstones or in mulch beds outdoors.
Wolf Spider
Wolf Spider AKA: Hairy Spider, Ground Spider Hogna carolinensis, Rabidosa spp.
0.5 to 1.5 in body; leg span up to 4 in. Much larger than woodlouse spider. Brown or gray with mottled or striped markings; no reddish-orange coloration. Brown or gray mottled body. Eight eyes in three rows including a prominent large central pair. No oversized chelicerae. Moves quickly across open surfaces. Does not rest inside a silk tube retreat under stones. Open garage floors, foundation entry points. Ground hunter active at night across open surfaces. Does not build silk tube retreats in hardscape gaps.
Southern House Spider
Southern House Spider (male) AKA: Crevice Weaver Kukulcania hibernalis
Male 0.4 to 0.5 in body. Dark brown to nearly black. No reddish-orange coloration. Long forward-projecting pedipalps often mistaken for oversized fangs. Dark brown to nearly black body (male). Very long forward-projecting pedipalps, not oversized chelicerae. Eight eyes. No reddish coloration. Builds distinctive woolly, cotton-candy web in window frame corners and eave crevices. Window frame corners, garage door frames, exterior eave crevices. Associated with a woolly web. Found on structures, not under patio pavers or in mulch beds.
The fastest field test for woodlouse spider identity: look at the color. A spider under your flagstone or flower pot with a reddish-orange or rust-colored front half and a pale cream or beige back half is a woodlouse spider. Brown recluse are uniformly matte tan to brown with no orange coloring anywhere. If you see orange or rust anywhere on the spider, it is not a brown recluse. That single visual check eliminates the only medically significant lookalike.
Why Woodlouse Spider Scores 1 of 3 on People Risk

People Risk for Woodlouse Spider

Woodlouse spiders look dangerous because of their oversized chelicerae and alarming defensive posture. They are not. Published peer-reviewed research on verified Dysdera crocata bites characterizes them as essentially innocuous: minor pain attributable largely to mechanical puncture from large fangs rather than any significant venom effect, with localized redness or mild swelling possible, resolving without treatment. There is no necrotic component, no systemic envenomation, and no documented medically serious outcome in the scientific literature.

People Risk
1/ 3
Low
Medical Risk

Woodlouse Spider Bites: What Actually Happens

Woodlouse spider bites are among the least medically significant spider bites a Collin County homeowner can receive. The 2006 Vetter et al. study in Toxicon (PMID 16574180) examined verified Dysdera crocata bites and found the primary symptom is minor pain, typically resolving within an hour, caused mainly by the mechanical puncture from the large fangs rather than any meaningful venom effect. Localized redness and mild swelling are possible. There is no necrosis, no systemic envenomation, no documented medical emergency from a confirmed woodlouse spider bite in the published literature. Vetter et al. 2006: Dysdera crocata bite study is the primary published source on this species’ bite effects.

The large chelicerae that produce so much alarm are adapted for cracking pill bug armor, not for injecting venom into large animals. The defensive posture the spider adopts when threatened (raising and spreading the chelicerae) looks threatening but is a physical deterrent display, not a precursor to an attack on a human. Bites occur only when the spider is physically pinned against skin, which happens when someone reaches blindly under a stone or presses a hand into mulch where the spider is resting. Wearing gloves when working in mulch beds or lifting pavers prevents the pinning scenario.

Worth Knowing
The Fangs Look Worse Than the Bite

The woodlouse spider has been classified in published bite literature as one of the least medically dangerous spiders homeowners actually encounter, despite being one of the most visually alarming. The fangs are sized for pill bug exoskeletons, not for injecting clinically relevant venom into humans. The threat display is real; the actual medical risk from a bite is not. Understanding this makes the practical response clearer: protection during yard work is the appropriate precaution, not emergency concern when the spider is spotted.

Context

When Woodlouse Spider Presence Warrants Action

Worth Addressing

Large Population Under Patio Hardscape

Finding multiple woodlouse spiders under flagstones or pavers when doing seasonal landscaping work means the pill bug population under that hardscape is high. Treating the spider without addressing the pill bug problem leaves the food source in place. A professional assessment targets pill bug control as the primary step, which reduces the woodlouse spider population by removing what keeps it there.

Worth Addressing

Repeated Indoor Encounters in Garage or Mudroom

Woodlouse spiders occasionally wander inside through garage thresholds and door sweeps during warm weather. Repeated indoor encounters indicate a large outdoor population adjacent to the structure. Indoor individuals do not establish and cannot breed inside, but treating the outdoor population and sealing the entry route resolves recurring interior sightings.

Low Priority

Single Spider Found Under One Paver

A single woodlouse spider under one flagstone, with no others found during inspection, is not a population problem. The spider is doing its job (eating pill bugs) and poses no risk. Replace the stone and leave it. If the pill bug population is not heavy on the property, the woodlouse spider will not multiply to nuisance levels.

Low Priority

Spider Found During Yard Work With No Indoor Presence

Finding a woodlouse spider while doing spring or fall yard work, with no indoor activity and no large outdoor population visible, requires only awareness and gloves. The spider is controlling your pill bug population and is not a hazard. The only action needed is to wear gloves when lifting stones or digging in mulch beds where the spider may be present.

Why Woodlouse Spider Scores 1 of 3 on Property Risk

Property Risk for Woodlouse Spider

Woodlouse spiders cause no property damage. They do not build prey-capture webs on structures, do not infest stored goods, and do not establish indoor colonies. Their shelter is outdoors under hardscape. The property concern is purely encountering them during yard work, not any damage they cause to the structure or its contents.

Property Risk
1/ 3
Low
Habitat

Where Woodlouse Spiders Come From in Collin County

Woodlouse spiders are fundamentally outdoor spiders. Their shelter is under hardscape: flagstones, patio pavers, landscape rocks, potted plant saucers, firewood piles, and any structure that creates a dark, slightly moist space above soil. During the day the spider rests inside its silk tube retreat tucked into the gap between the underside of a stone and the soil. At night it emerges to hunt in the surrounding area, primarily targeting pill bugs and sowbugs in mulch beds and irrigated planting zones. It may travel several meters from its retreat in a single hunting session.

Indoor encounters happen when individual spiders wander in through garage thresholds, door sweeps, or gaps along patio door frames, particularly in warm weather. Indoor woodlouse spiders are migrants from outdoor populations. They cannot sustain breeding inside a home. An indoor woodlouse spider is a wanderer; there is no indoor nest or colony behind it. The outdoor population adjacent to the structure is the source of all indoor encounters, which is why exterior treatment is the effective response rather than treating interior surfaces.

Local Presence

Woodlouse Spider Presence Across Collin County

Woodlouse spider pressure tracks closely with landscape investment and pill bug population. The highest-activity properties in Collin County are those with extensive flagstone or paver hardscape: McKinney neighborhoods like Stonebridge Ranch, Adriatica, and Tucker Hill with significant patio and walkway installations. Allen Twin Creeks properties with mature trees, shade, and established mulch beds create ideal pill bug habitat that supports woodlouse spider populations. Pool and patio homes with decorative rock features and stacked stone water features throughout Frisco and Plano provide shelter volume that sustains larger populations.

Properties with minimal hardscape and lower pill bug pressure see few if any woodlouse spiders. The spider follows the prey rather than establishing independently. Newer construction in Celina and Prosper may see pressure building as mulch beds mature and pill bug populations develop with the landscape.

Why Woodlouse Spider Scores 2 of 3 on Persistence Risk

Woodlouse Spider Biology and Seasonal Presence

Woodlouse spiders are persistent because their food source is persistent. Pill bugs and sowbugs thrive year-round in Collin County mulch beds, irrigated planting zones, and under hardscape. As long as the prey base is present, woodlouse spiders will recolonize treated areas within weeks. This is the defining characteristic that separates woodlouse spider control from most other spider management: treating the spider without addressing the pill bug population produces only temporary results.

Persistence Risk
2/ 3
Moderate
Behavior and Biology

Woodlouse Spider Biology Worth Knowing

Specialist Predator Primary prey is pill bugs and sowbugs; chelicerae specifically adapted for piercing calcified crustacean exoskeleton Dysdera crocata is one of the few spider species capable of routinely preying on pill bugs (Armadillidium vulgare) and sowbugs (Porcellio spp.). The oversized chelicerae allow one fang to strike from above and the other from below in a coordinated pincer motion that cracks the calcified shell. Most other spider species cannot pierce this armor at all. When pill bugs are scarce, Dysdera will take silverfish, earwigs, small beetles, and crickets, but its population tracks pill bug abundance more closely than any other food source.
Nocturnal Hunting Rests in silk tube retreat during day; emerges at night to actively hunt; may travel several meters from retreat in a single session Unlike jumping spiders or wolf spiders that are visible in daylight, the woodlouse spider is almost exclusively nocturnal. It spends daylight hours inside a small silken tube tucked under a stone or paver. At night it emerges and walks its hunting territory searching for pill bugs. This is why homeowners almost never see the spider under normal circumstances: it is hidden during the day, and the encounter happens only when a stone is lifted that exposes the daytime retreat. The silk tube inside the gap is a diagnostic feature: if a small tube of silk is visible when you lift the stone, a woodlouse spider occupies or recently occupied that retreat.
Lifecycle Slow development: about 1 to 1.5 years to maturity; field lifespan of several years possible Dysdera crocata matures slowly relative to many house spider species. Females lay eggs in a loose silk cocoon typically inside the retreat. The slow lifecycle means a woodlouse spider population builds gradually on a property as conditions develop, rather than exploding rapidly the way cellar spider populations can. However, the same slow lifecycle means that once a population is established, it is persistent: eliminating it requires removing both the spiders and the conditions (pill bug abundance, shelter availability) that allowed it to build.
Eye Arrangement Six eyes in a tight compact oval cluster; completely different from brown recluse’s three separated pairs Both woodlouse spiders and brown recluse have six eyes rather than the eight eyes of most other spider families. This is a key identification point: six eyes narrows the field significantly in Texas. But the arrangement is the critical diagnostic difference. Brown recluse have six eyes arranged in three distinct, widely-spaced pairs in a semicircle. Dysdera crocata has six eyes in a tight, compact oval cluster. Even at distance, the distinction between three separated pairs and one tight oval cluster is usually visible with a camera zoom. When in doubt, photograph the eyes.
Mediterranean Origin Native to Mediterranean basin; spread globally through trade as a stowaway in soil and potted plants Dysdera crocata is not native to North America. It is an introduced species that spread worldwide over centuries as a hidden passenger in soil and potted plant trade. Its presence across the eastern and central United States, including Texas, reflects long-term establishment as a naturalized species. The spider is well-adapted to urban and suburban landscapes because it followed pill bugs, which are themselves non-native crustaceans that thrive in the same mulched, irrigated suburban landscape that defines most of Collin County’s residential neighborhoods.
Recolonization Rate Returns within weeks when pill bug population is not reduced; prey base is the limiting factor for population size The most practical persistence fact for pest management: woodlouse spider numbers are a downstream indicator of pill bug abundance. Remove the pill bugs and the woodlouse spider has no reason to stay and no food source to support reproduction. Treat the spider without removing the pill bugs and the population rebuilds from adjacent areas within weeks. Every durable woodlouse spider management outcome in PMO service records includes pill bug control as the primary intervention.
Pest Me Off Translation
Chelicerae→ The fangs sticking out the front of the spider’s face. On the woodlouse spider they are disproportionately large because they are built for cracking pill bug armor, not for threatening people.
Silken retreat→ The small tube of silk tucked into the gap under a flagstone or paver where the spider spends the day. If you see a small silk tube when you lift a stone, there is probably a woodlouse spider inside or very nearby.
Isopod prey base→ The pill bug and sowbug population in your mulch beds and under your pavers. This is what the woodlouse spider is eating. Reduce the pill bugs and you reduce the spider. Treat only the spider and it comes back.
Reality Check

Things You Should Know About Woodlouse Spiders

Facts that make the encounter make sense and guide a proportionate response

1
The woodlouse spider is not a brown recluse, and the color tells you immediately.Why this matters. The most common first reaction to finding a woodlouse spider is “brown recluse.” The fangs trigger alarm and the hardscape context can briefly match the mental picture of a “spider in a hiding spot.” But brown recluse are uniformly matte tan to brown. No orange, no rust, no reddish coloring anywhere. If any part of the spider is orange or rust-colored, it is not a brown recluse. The woodlouse spider’s two-tone color pattern closes the identification for anyone who can see the spider clearly in any reasonable light.
2
The oversized fangs are for cracking pill bug armor, not for attacking humans.Why this matters. The chelicerae that produce so much alarm evolved for one specific purpose: piercing the calcified shell of a pill bug. One fang strikes from above, the other from below, cracking a defensive layer that most other spider species cannot penetrate at all. They are not sized for injecting venom into large animals. The spider will display them in a defensive posture when threatened, which looks alarming. That display is the spider saying leave me alone. It is not preparation for an attack on a human.
3
Treating the spider without addressing the pill bug population is the most common management failure.Why this matters. A property with deep mulch beds and heavy pill bug pressure will recolonize with woodlouse spiders within weeks of a perimeter spray that eliminates only the spiders. The prey base pulls the spider back. This is why every durable woodlouse spider outcome in PMO service history includes isopod control as the first step. The spider is a symptom. The pill bug population is the condition.
4
The silk tube under the stone is the spider’s daytime retreat, not an egg sac or web.Why this matters. When a flagstone is lifted and a small tube of silk is visible in the gap beneath it, some homeowners assume it is a dangerous egg sac or a web associated with a venomous spider. It is the woodlouse spider’s sleeping quarters: a small silken tube where the spider waits out the day. The spider is either inside the tube or very nearby. This is useful diagnostic information for a PMO tech confirming the species and locating the retreat for treatment.
5
The species spread globally as a stowaway in potted plant trade from the Mediterranean.Why this matters. Understanding that this is an introduced species explains why it is found consistently in suburban landscapes rather than native habitat. It followed pill bugs, which are themselves introduced crustaceans that thrive in the same mulched, irrigated conditions that define Collin County residential landscaping. Both species are beneficiaries of the suburban landscape. Managing one requires managing the other.
Why Woodlouse Spider Scores 2 of 3 on Difficulty to Treat

Managing Woodlouse Spider Populations

Woodlouse spider treatment is moderately challenging because a single-layer approach fails. Surface-only perimeter spray does not penetrate silk tube retreats under flagstone. Treating only the spider without reducing the pill bug population produces temporary results. Effective management requires three coordinated steps: pill bug population control, shelter reduction, and direct perimeter treatment. All three working together produce lasting results. Any one alone produces only partial and temporary results.

Difficulty to Treat
2/ 3
Moderate
SPIDER CONTROL
Management

How Pest Me Off Handles Woodlouse Spider

When we service a property with woodlouse spider activity, the treatment plan starts with the pill bug population, not the spider. We assess the mulch bed conditions, irrigation patterns, and hardscape volume before selecting products. The spider is addressed directly through perimeter treatment and shelter recommendations, but the lasting outcome depends on reducing what brings the spider to the property in the first place.

Step 1

Confirm Species and Assess Shelter

Visually confirm the reddish-orange cephalothorax and pale abdomen. Look for the silken tube retreat under the flagstone where the spider was found. Assess pill bug population in surrounding mulch beds and under adjacent pavers. The shelter count and pill bug pressure determine how aggressive treatment needs to be and whether shelter reduction is both feasible and necessary for lasting results.

Why this step: Positive identification confirms the species and eliminates brown recluse concern immediately. The shelter and pill bug assessment determines which treatment combination will hold.
Step 2

Pill Bug and Sowbug Population Control

Apply dry bait and liquid products labeled for isopods to mulch beds, foundation edges, paver joints, and any other area with visible pill bug activity. This step directly reduces the prey base that sustains the woodlouse spider population. Properties with high pill bug pressure require this step first; skipping it produces only temporary spider reduction.

Why this step: Woodlouse spider numbers are directly tied to pill bug abundance. A property with high pill bug pressure will recolonize with woodlouse spiders within weeks of treating only the spider. This step is what separates treatments that last from treatments that require repeat visits every few weeks.
Step 3

Shelter Modification

Reduce unnecessary shelter: reduce mulch depth to two inches or less where possible, reset settled flagstones with crushed stone beneath rather than soil to eliminate the moist gap where retreats form, remove firewood piles from foundation contact, eliminate decorative stones not serving a structural purpose, and clear potted plant saucers that collect moisture. These changes make the area less hospitable to both pill bugs and woodlouse spiders without chemical application.

Why this step: Chemical treatment addresses the current population. Shelter modification prevents the next one. Properties that modify shelter along with chemical treatment see sustained reduction; properties that treat only chemically but leave deep mulch and high shelter volume see recurring activity.
Step 4

Perimeter Treatment at Paver Edges and Foundation

Apply liquid residual along the foundation line, paver and flagstone edges, patio perimeter, and landscape timber borders. Focus on the edges where hardscape meets soil, which is the travel corridor between retreats and hunting areas. Treat paver joints where accessible. For indoor wanderers, treat garage perimeter, slab expansion joints, and exterior door thresholds with residual product.

Why this step: Direct perimeter treatment addresses the spider’s travel corridors. Surface spray that does not reach into hardscape gaps and paver joints misses the retreats entirely. Treatment at the paver edges and foundation line is where the spider travels between retreats and hunting areas.
Pest Me Off
Identify the spider and confirm it is not a brown recluse. Assess pill bug population and shelter volume. Treat pill bugs first as the primary step. Apply perimeter treatment at paver edges and foundation. Recommend shelter reduction for lasting results. Follow up to confirm pill bug control is working. Done in one or two visits with lasting results when pill bug control succeeds.
Store Products
& Other Companies
Spray perimeter for spiders. Kill visible spiders temporarily. Pill bug population remains unchanged in mulch beds. Woodlouse spiders recolonize from adjacent areas within three to six weeks. Surface spray misses retreats under flagstone. Recommend repeat quarterly visits without addressing the underlying pill bug problem. Spider activity continues because the food source was never addressed.
Do It Yourself
Woodlouse Spider: DIY Steps That Work and Steps That Fail
Surface spray alone does not solve this – address the pill bugs first
DIY Management

DIY Woodlouse Spider Management

DIY management for woodlouse spiders is possible with the right sequence. Target pill bugs first, then shelter, then the spider itself.

1
Reduce mulch depth. Deep mulch beds (more than two to three inches) create ideal pill bug habitat: moist, dark, insulated from temperature extremes. Reducing mulch depth removes the environment pill bugs need to thrive at high population densities. Less pill bug pressure directly reduces woodlouse spider pressure. This is the single highest-impact DIY step on a property with heavy mulch beds.
2
Apply dry bait isopod control to mulch beds. Dry bait products labeled for pill bugs and sowbugs, broadcast into mulch beds and foundation edges, are effective at reducing pill bug population. Read and follow label directions. A reduction in pill bug population within two to three weeks will be visible. Woodlouse spider activity will follow the same downward trend.
3
Reset flagstones over crushed stone rather than soil. The gap between the underside of a flagstone and moist soil is ideal silk retreat habitat. Resetting flagstones with a dry-packed crushed stone base eliminates the moist gap and makes the space under the stone less hospitable as a retreat. This is a permanent shelter reduction that does not require ongoing chemical application.
4
Wear gloves when lifting pavers or working in mulch beds. The only realistic bite scenario is pinning the spider against skin when it cannot escape. Gloves eliminate this risk entirely. If you are doing seasonal landscaping work in a yard with woodlouse spider activity, gloves are the complete personal protection solution.
DIY Pitfalls

Why Some DIY Responses Fail for Woodlouse Spiders

Wrong Target

Treating the Spider Without Addressing Pill Bugs

The most common DIY failure. Spraying a perimeter spider treatment without reducing the pill bug population eliminates the current spiders and leaves the food source intact. Woodlouse spiders from adjacent yard areas recolonize within three to six weeks. The property has the same pill bug population supporting the same woodlouse spider population, just delayed. Pill bug control before spider treatment is the sequence that produces lasting results.

Reach Problem

Surface Spray That Cannot Reach Under Hardscape

Woodlouse spiders live inside silk tube retreats tucked into the gap under flagstones and pavers. A surface spray applied to the top of paver edges does not penetrate into those gaps. Effective treatment targets the edges where pavers meet soil and the foundation line where the spider travels at night, not the stone surfaces themselves.

Misidentification

Treating for Brown Recluse Based on Misidentification

A homeowner who misidentifies a woodlouse spider as a brown recluse may apply indoor brown recluse treatments (sticky traps in closets, treatment behind furniture) in the wrong locations entirely. Brown recluse treatments target indoor undisturbed storage spaces. Woodlouse spiders live outdoors under flagstone and pavers. Treating the inside of the house for a spider that is living outside under the patio is an expensive misapplication that solves nothing.

Panic Response

Emergency Interior Treatment for an Outdoor Spider

A woodlouse spider found wandering inside a garage is a migrant from an outdoor population. It cannot establish or breed inside. Fogging or bombing the interior introduces pesticide exposure for a spider that does not live indoors. The outdoor source population is untouched. The correct response: remove the individual spider, treat the outdoor perimeter, and address pill bug pressure in the adjacent mulch beds.

Timing

Treating Once and Expecting Lasting Results

A single perimeter treatment in spring removes the spiders present that day. It does not prevent recolonization from adjacent yard areas when the pill bug population is not reduced. Properties with active mulch beds and continuous irrigation rebuild woodlouse spider activity within three to six weeks of a one-time spray. Two to three follow-up applications combined with pill bug control sustain results through the full active season. One visit is a start, not a solution.

Operational Questions

Common Woodlouse Spider Questions

The name comes from what it eats. A woodlouse is the British name for the crustacean most Americans call a pill bug or roly-poly (Armadillidium vulgare), the small armored creature that rolls into a ball in mulch beds. Dysdera crocata specializes in hunting them, using oversized chelicerae designed to pierce the calcified shell that defeats most other spiders. The name woodlouse hunter describes the behavior exactly. Other common names, including pill bug spider and sowbug spider, describe the same prey relationship. Most Collin County homeowners encounter this spider long before they learn any of its names, calling it “the scary red-orange spider under my flagstone.”
That is almost certainly a woodlouse spider (Dysdera crocata). The vivid reddish-orange or rust-colored front half with a pale cream abdomen, combined with the disproportionately large forward-projecting fangs (chelicerae), are diagnostic. It is not a brown recluse: brown recluse are uniformly matte tan to brown with no orange coloring anywhere on the body. The woodlouse spider is not medically dangerous. Its fangs are sized for cracking pill bug armor, not for injecting significant venom into humans. Published bite research classifies it as one of the least medically dangerous spiders homeowners encounter.
No. The color eliminates the brown recluse immediately. Woodlouse spiders are reddish-orange in front with a pale abdomen. Brown recluse are uniformly matte tan to brown with no reddish or orange coloration anywhere. Brown recluse are also found in undisturbed indoor storage spaces, not under flagstones or patio pavers in the yard. If you found an orange or rust-colored spider under a stone in your yard, it is a woodlouse spider. The locations and colors of these two species are completely different.
No. The woodlouse spider’s medical significance is LOW. Published bite research (Vetter et al., 2006, Toxicon) on verified Dysdera crocata bites found minor localized pain that resolves within an hour, attributable largely to the mechanical puncture from large fangs rather than any meaningful venom effect. There is no necrosis, no systemic effect, and no documented medically serious outcome from a confirmed woodlouse spider bite. Pets that investigate the spider are unlikely to experience any significant reaction. Normal caution applies: do not handle the spider, and wear gloves when working in areas with known activity.
The oversized chelicerae are specifically adapted for piercing the calcified exoskeleton of pill bugs and sowbugs, which is the woodlouse spider’s primary prey. One fang strikes from above and the other from below in a coordinated pincer grip that cracks the shell. Most other spider species cannot pierce pill bug armor at all. The fangs that look alarming to homeowners are functional tools for the spider’s specialized diet, not weapons sized for threatening large animals. The spider will display them in a defensive posture when threatened, which looks intimidating but is a deterrent display, not preparation for a dangerous attack on a human.
Woodlouse spiders live under flagstones, patio pavers, landscape rocks, potted plant saucers, firewood piles, and mulch beds adjacent to the foundation. They build small silk tube retreats in the gap between the underside of a stone and the soil below it. During the day the spider is inside the retreat. At night it emerges to hunt pill bugs and sowbugs in the surrounding area. The highest-activity properties in Collin County are those with extensive flagstone patios or paver walkways and heavy mulch beds: Stonebridge Ranch and Tucker Hill in McKinney, Allen Twin Creeks, and pool and patio homes with decorative rock features throughout the service area.
The most effective sequence: first, reduce the pill bug and sowbug population in your mulch beds using dry bait or liquid isopod control products. Second, reduce mulch depth to two inches or less where possible, and remove firewood piles from foundation contact. Third, apply perimeter treatment along paver edges and foundation lines where the spider travels at night. This three-step approach produces lasting results. Treating only the spider without reducing pill bugs produces temporary results because the food source remains and woodlouse spiders recolonize within weeks. The pill bug population is the lever that matters most.
No. Woodlouse spiders inside a garage or mudroom are almost always individual wanderers from an outdoor population adjacent to the structure. They cannot establish or breed indoors. An indoor woodlouse spider is a migrant, not a colony. Remove the individual spider and treat the outdoor perimeter and adjacent mulch beds where the outdoor population lives. The source of the indoor encounter is outside the structure, not inside it.
That is a woodlouse spider’s silk retreat: the small tube of silk inside the gap under the stone where the spider rests during the day. The spider is either inside the tube or very nearby when you lift the stone. This tube retreat is a diagnostic feature that confirms woodlouse spider activity. It is not a dangerous egg sac. It is not associated with a web-building spider. The woodlouse spider does not build prey-capture webs. The silk tube is its sleeping quarters only. If you find it when lifting a stone, the woodlouse spider that built it will be visible nearby or emerge when the stone is lifted and light enters.
Yes, on properties with the right conditions. Woodlouse spiders are present across Collin County wherever pill bug populations are high and hardscape shelter is available. Properties with flagstone patios, paver walkways, deep mulch beds, and regular irrigation are the most consistent locations. McKinney neighborhoods with significant landscape investment, including Stonebridge Ranch, Adriatica, and Tucker Hill, see regular activity. Allen Twin Creeks and established Plano neighborhoods with mature landscaping are also consistent locations. Properties with minimal hardscape and lower pill bug pressure see little to no woodlouse spider activity.
Their primary prey is pill bugs (Armadillidium vulgare) and sowbugs (Porcellio species), which are the small armored crustaceans commonly called roly-polies that live in moist soil and mulch. The woodlouse spider’s oversized chelicerae are specifically adapted for piercing the calcified shell of these crustaceans. When pill bugs are scarce, Dysdera crocata will also take silverfish, earwigs, small beetles, and crickets. The strong correlation between pill bug population and woodlouse spider population means that any property with a heavy pill bug problem is a potential host for woodlouse spiders.
Color is the immediate distinguishing feature. Woodlouse spiders are reddish-orange in front with a pale abdomen. Southern house spiders are dark brown to nearly black (males) or brown (females) with no orange coloration. Southern house spiders build a characteristic woolly, cotton-candy web in window frame corners and garage door frame crevices; woodlouse spiders build a small silk tube retreat under hardscape and do not build prey-capture webs. Southern house spiders are found on structures; woodlouse spiders are found in the yard under stones and in mulch beds.
No significant concern. Woodlouse spider bite risk is LOW. Published research on verified bites found only minor localized pain resolving within an hour, with no necrosis and no systemic effect. If a child encountered the spider but was not bitten, no action is needed. If a bite occurred, monitor for localized redness that should resolve quickly without treatment. Normal common sense applies: discourage handling of any spider, including this one.
What's Bugging You?

Red Spider Under Your Flagstone. Looks Scary. Not What You Think It Is.

We identify it in seconds and tell you what it actually is and what it actually takes to get rid of it. If it is a woodlouse spider, the pill bug problem in your mulch beds is what we address first. That is what produces a lasting result. McKinney, Allen, Frisco, Plano, and all of Collin County.

12Stops Per Day
Other companies run 20+ stops a day. We cap at 12. That extra time is what it takes to correctly identify the spider, explain why surface spray alone will not solve it, and build a treatment plan that addresses both the spider and the pill bug population that keeps bringing it back.
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