Woodlouse Hunter, Woodlouse Spider, Sowbug Killer
Dysdera crocata
Dysderidae (Woodlouse Hunters), Order Araneae
Physical Description
Characterized by an elongated, cylindrical cephalothorax and an oval, smooth abdomen. The most striking feature is its disproportionately large, forward-projecting chelicerae (fangs), which are adapted for piercing the armor of isopods.
Size Estimate
Body length 9-15mm (females larger); leg span roughly 25-35mm. This appears to be an adult specimen.
Coloration & Markings
Distinctive bi-colored appearance: the cephalothorax and legs are a deep reddish-brown to dark orange, while the abdomen is a pale, creamy grey, tan, or yellowish-buff with no visible patterns.
Web Type
The woodlouse hunter does not spin a web for catching prey. It is a free-roaming hunter that builds small silk retreats or sacs in secluded areas to rest and molt.
Eye Arrangement
Six eyes (rather than the typical eight) arranged in a tight semi-circle or oval cluster at the front of the head, which is a key diagnostic feature for the family Dysderidae.
Leg Characteristics
The legs are moderately long, robust, and smooth with a reddish-orange hue, matching the cephalothorax. They lack prominent banding or thick spines.
Venom & Safety Information
Venom Information
Neurotoxic venom specialized for paralyzing invertebrates. It is not considered toxic to humans, though the large fangs can facilitate a deep, painful mechanical bite.
Medical Significance
Low danger level. A bite may cause localized pain, redness, and minor itching (similar to a bee sting), but symptoms typically resolve within hours. No specialized treatment is usually required.
Safety Recommendations
If found indoors, relocate using the cup-and-paper method to a garden or woodpile. Wear gloves when gardening in leaf litter to avoid accidental 'pinch' bites.
Habitat & Behavior
Habitat & Range
Found globally (cosmopolitan), including North America, Europe, and Australia. They prefer damp, dark microhabitats such as under logs, rocks, leaf litter, and occasionally in basements or near foundations.
Behavior & Temperament
Nocturnal and solitary. They are active hunters that stalk prey at night. While they look intimidating due to their large fangs, they are generally non-aggressive toward humans and will flee unless handled or cornered.
Diet & Prey
Specializes almost exclusively on woodlice (sowbugs/pillbugs). Its elongated fangs allow it to reach around and pierce the soft underbelly or the hard exoskeleton of terrestrial isopods.
Seasonal Activity
Active year-round in warmer climates; in temperate zones, they are most visible during spring and summer mating seasons when males wander.
Description
The Woodlouse Hunter is a visually striking spider often found near homes. With its 'baked bean' colored abdomen and blood-red front half, it is an unmistakable predator of the garden's armored crustaceans.
Key Features
Reddish-brown cephalothorax, cream-colored abdomen, six eyes in a cluster, and exceptionally large, forward-facing chelicerae.
Similar Species
Broad-faced sac spiders (Trachelas tranquillus) have similar colors but smaller fangs and eight eyes. Ground spiders (Gnaphosidae) lack the specialized fangs and cylindrical body shape.
Life Cycle
Females lay about 70 eggs in a silk sac within their retreat. They exhibit some maternal care, guarding the eggs. They can live for 2-3 years, a relatively long lifespan for a small spider.
Ecological Importance
Significant natural pest control in gardens and around homes, regulating populations of woodlice and other soil-dwelling invertebrates.
Conservation Status
Not evaluated by the IUCN; generally considered common and stable due to their wide range and adaptation to human environments.
Interesting Facts
The fangs are so long and powerful that they can pierce through human fingernails, though the spider rarely has reason to do so. They are one of the few spiders specialized to eat 'crunchy' prey.
Photography Tips
Focus on the head area to capture the unique six-eye arrangement and the massive chelicerae. Use a side or top-down angle to highlight the color contrast between the two body segments.
Identified: 2026-07-16T05:42:33.366315