Woodlouse Hunter, Sowbug-killer, Woodlouse Spider
Dysdera crocata
Dysderidae (Woodlouse Hunters), Order Araneae. Characterized by six eyes and large, forward-facing chelicerae (fangs).
Physical Description
A medium-sized spider with a smooth, glossy texture. The cephalothorax is dark reddish-brown and oval-shaped, while the abdomen is a contrasting creamy-grey, tan, or beige with a satiny sheen. It possesses exceptionally long, protruding fangs (chelicerae).
Size Estimate
Body length is typically 9–15 mm (0.35–0.6 in). Total leg span ranges from 25–40 mm. Common adults are roughly the size of a U.S. nickel including legs.
Coloration & Markings
Distinctive bi-colored appearance: the front half (prosoma) and legs are deep orange to reddish-brown; the rear half (opisthosoma) is uniform greyish-white, buff, or pale yellow without visible patterns.
Web Type
This is a hunting spider that does not use webs to capture prey. Instead, it spins a small, silk-lined retreat or 'sac' under logs or rocks to rest and molt.
Eye Arrangement
Six eyes (rather than the typical eight) arranged in a tight semi-circle or oval grouping at the front of the cephalothorax.
Leg Characteristics
Six reddish-orange legs, relatively long and slender. They lack heavy banding but have a smooth, polished appearance.
Venom & Safety Information
Venom Information
Neurotoxic venom specialized for arthropods. For humans, it is considered very low potency and is not medically significant.
Medical Significance
Low danger level. Bites are painful due to mechanical puncture from large fangs, but effects are typically limited to localized redness, itching, and minor swelling that subsides within hours.
Safety Recommendations
Avoid handling with bare hands due to the pinch-like bite. If found indoors, they can be easily relocated using a cup and a piece of paper. They are more beneficial than harmful.
Habitat & Behavior
Habitat & Range
Cosmopolitan distribution; widely found in North America, Europe, and Australia. They prefer moist areas under rocks, logs, leaf litter, and are common in basements or gardens near woodpiles.
Behavior & Temperament
Nocturnal active hunter. They are generally shy and will retreat if disturbed, but can be defensive if handled, often rearing up to display their large fangs.
Diet & Prey
Specializes in eating woodlice (sowbugs/pillbugs). Their elongated fangs are an evolutionary adaptation designed to pierce the tough exoskeleton of these crustaceans.
Seasonal Activity
Active year-round in temperate climates, though most frequently encountered by humans in spring and autumn when they wander in search of mates or moisture.
Description
An striking hunter known for its 'pillbug' diet, the Woodlouse Hunter is a common sight in urban gardens. Its vibrant red thorax and pale abdomen make it easy to spot, while its oversized fangs highlight its role as a specialized predator of armored garden pests.
Key Features
Reddish-brown cephalothorax, pale cream abdomen, six eyes in a group, and very long, forward-jutting fangs.
Similar Species
Broad-faced sac spiders (Trachelas tranquillus) have similar colors but different eye patterns and smaller fangs. Brown recluses are tan/brown with a violin shape and lack the distinct red-front/pale-back contrast.
Life Cycle
Females lay eggs in silk retreats and provide basic maternal care. Unlike many spiders, they do not show aggression toward mates. They can live for 2 to 3 years.
Ecological Importance
Significant natural pest control in gardens and basements, as they are one of the few predators that actively target woodlice and sowbugs.
Conservation Status
Not evaluated by IUCN; considered very common and stable in population worldwide.
Interesting Facts
Despite their intimidating fangs, they are almost strictly 'crustacean hunters.' Their fangs work like pliers to flip woodlice over or pierce through the joints in their armor.
Photography Tips
Focus on the front of the head to capture the fangs and the six-eye arrangement. High-contrast lighting helps distinguish the gradient between the red cephalothorax and pale abdomen.
Identified: 2026-06-30T13:23:56.462454