Woodlouse Spider, Woodlouse Hunter, Pillbug Hunter
Dysdera crocata
Dysderidae (Woodlouse Spider Family), Order Araneae. Key family characteristics include six eyes arranged in a compact, tight cluster and distinctly enlarged, elongated chelicerae adapted for piercing hard-shelled prey.
Physical Description
Elongated body with a smooth, shiny, dark reddish-brown to orange cephalothorax and a pale beige, yellowish, or grayish-pink elongated oval abdomen. Most notable for its disproportionately large, forward-pointing dark red fangs (chelicerae).
Size Estimate
Body length typically ranges from 11 to 15 mm for females and 9 to 10 mm for males, with a relatively short, compact leg span. The specimen pictured appears to be a typical adult or sub-adult.
Coloration & Markings
Characterized by a striking contrast: a deep reddish-orange head and legs paired with a dull, pale greyish-pink or beige abdomen lacking complex patterns or markings.
Web Type
Does not build a traditional prey-capturing web. Instead, it constructs a silken retreat or nocturnal hiding sac under rocks, logs, bark, or leaf litter where it rests during the day.
Eye Arrangement
Six eyes arranged closely together in a compact, forward-facing oval cluster on the front top of the cephalothorax.
Leg Characteristics
Legs are relatively short, robust, reddish-orange, and covered in fine hairs or spines, adapted for gripping rough surfaces rather than rapid running.
Venom & Safety Information
Venom Information
Low-toxicity venom primarily specialized for subduing hard-shelled invertebrates. Not considered dangerous to humans.
Medical Significance
Harmless to humans. While their large fangs can deliver a sharp, pinprick-like mechanical pinch that may break the skin, the venom is not medically significant and typically causes only minor, temporary localized irritation.
Safety Recommendations
No special precautions needed. If found indoors, gently cup the spider under a glass and slide a piece of paper underneath to safely release it outdoors in a garden or woodpile.
Habitat & Behavior
Habitat & Range
Cosmopolitan distribution, native to Europe but widely introduced globally including North America, Australia, and New Zealand. Prefers damp terrestrial microhabitats such as under stones, logs, garden debris, and occasionally inside homes.
Behavior & Temperament
Nocturnal active hunter. Spends daylight hours hidden in a silken cell. Generally docile and reluctant to bite unless directly trapped or squeezed against skin.
Diet & Prey
Specialized feeder with a primary diet of woodlice (isopods, pillbugs, sowbugs). Uses its massive fangs to pierce the tough calcified shells of isopods.
Seasonal Activity
Active from spring through autumn, reaching peak visibility during damp weather conditions. Overwinters by retreating deep under logs, stones, or into soil crevices.
Description
The Woodlouse Spider is an easily recognizable garden visitor famous for its specialized hunting lifestyle. With a glossy reddish-orange armor and intimidating forward-facing fangs, it is a formidable subterranean predator specialized in hunting pillbugs.
Key Features
Brilliant reddish-orange cephalothorax and legs, pale pinkish-beige abdomen, six eyes in a tight cluster, and exceptionally large, prominent forward-pointing chelicerae.
Similar Species
Can sometimes be confused with ground spiders (Gnaphosidae) or broad-faced sac spiders (Trachelidae), but neither possesses the extreme elongated fangs and specialized six-eye grouping of the woodlouse spider.
Life Cycle
Females construct a silken egg sac where they lay around 70 eggs. Spiderlings remain with the mother briefly after hatching. They molt multiple times to reach maturity and can live for up to several years.
Ecological Importance
Serves as an effective natural predator of garden woodlice (pillbugs), helping regulate isopod populations in gardens and forested environments.
Conservation Status
Not evaluated by the IUCN, but populations are secure, widespread, and frequently benefit from human agricultural and suburban landscapes.
Interesting Facts
Despite their fierce appearance, they are completely harmless to humans. Their massive fangs are evolutionary marvels perfectly engineered to pierce the armor-like exoskeleton of woodlice.
Photography Tips
Macro photography works best. Use diffused natural lighting to capture the texture and glossy finish of the reddish cephalothorax and the massive fangs without harsh glares.
Identified: 2026-08-21T05:33:46.613849