Woodlouse Hunter, Woodlouse Spider, Sowbug-killer, Slater-killer
Dysdera crocata
Family Dysderidae (Woodlouse Hunters), Order Araneae. Key family features include only six eyes and very large, forward-pointing chelicerae (fangs).
Physical Description
A medium-sized spider with a smooth, glossy cephalothorax and an elongated, oval-shaped abdomen. It is characterized by exceptionally large, forward-projecting chelicerae (fangs) relative to its body. The body is hairless in appearance, with a hard, leathery texture on the cephalothorax.
Size Estimate
Body length 9-15mm (females) and 7-10mm (males). Leg span can reach 25-30mm. This specific specimen appears to be an adult.
Coloration & Markings
Strongly bicolored: the cephalothorax and legs are dark orange, reddish-brown, or deep mahogany. The abdomen is a contrasting pale grey, beige, or creamy-tan with no distinct markings or patterns.
Web Type
The Woodlouse Hunter does not build a web to catch prey. It is an active nocturnal wanderer. It only spins silk to create a small, silken 'sleep-sac' or retreat used for molting, laying eggs, and daytime resting.
Eye Arrangement
Uncommon eye pattern consisting of only six eyes (most spiders have eight). The eyes are arranged in a tight semi-circular or oval cluster at the front of the cephalothorax.
Leg Characteristics
Legs are moderately long and thick, matching the orange-red color of the cephalothorax. They lack prominent banding but may have small, fine spines. They are adapted for navigating leaf litter and tight crevices.
Venom & Safety Information
Venom Information
The venom is not medically significant to humans. While the bite is painful due to the mechanical size of the fangs, the venom is primarily designed to paralyze small arthropods and lacks potent neurotoxins or cytotoxins harmful to humans.
Medical Significance
Low danger level. Bites are rare and usually happen when the spider is pressed against skin (e.g., inside a shoe). Symptoms includelocalized sharp pain, redness, and minor swelling lasting a few hours. No treatment is usually required beyond cleaning the site.
Safety Recommendations
Relocate using a cup and paper if found indoors. To prevent them entering, seal cracks in foundations and reduce moisture around the home. If bitten, wash with soap and water; use a cold compress for pain.
Habitat & Behavior
Habitat & Range
Cosmopolitan distribution due to human trade; native to the Mediterranean but now found throughout North America, Europe, Australia, and parts of South America. Prefers damp, dark places like under logs, rocks, flowerpots, and in basements.
Behavior & Temperament
A solitary nocturnal predator. It is shy and typically tries to flee when uncovered, but it can be defensive and 'gape' its large fangs if cornered or handled. It relies on its powerful bite rather than speed to secure prey.
Diet & Prey
A specialized hunter of woodlice (isopods/pill bugs/roly-pollies). Their massive fangs are specifically evolved to pierce the hard, armored exoskeletons of woodlice. They also eat other small ground-dwelling invertebrates.
Seasonal Activity
Active year-round in temperate climates, though most often encountered indoors during spring and autumn. In winter, they overwinter in their silken retreats under debris or in wall voids.
Description
This striking, two-toned spider is a master of the garden floor. Often mistaken for more dangerous species due to its fierce-looking fangs and reddish hue, the Woodlouse Hunter is actually a beneficial predator that helps manage populations of isopods in gardens and basements. Its distinctive orange-red head and pale abdomen make it instantly recognizable to those who know it.
Key Features
Large, forward-facing chelicerae; dark reddish cephalothorax contrasting with a cream/grey abdomen; six eyes in a tight cluster; lack of abdominal patterns.
Similar Species
Broad-faced sac spiders (Trachelas spp.) have similar colors but smaller fangs and eight eyes. Brown Recluse (Loxosceles reclusa) is uniform tan with a violin shape and different eye arrangement.
Life Cycle
Mating involves a complex ritual where the male uses his long fangs to hold the female's fangs open to avoid cannibalism. Silk egg sacs are hidden in retreats. Lifespan is approximately 2 to 3 years, which is long for a small spider.
Ecological Importance
Critical for controlling isopod and sowbug populations. They act as a natural pest control agent in gardens and greenhouses, maintaining the balance of decomposing organisms in the soil food web.
Conservation Status
Not listed by IUCN; it is a stable and widespread species. It is considered an introduced but naturalized species in many parts of the world.
Interesting Facts
The fangs are so long that they are almost half the length of the cephalothorax. They act like pliers, one fang reaching under the woodlouse while the other pierces the top. They are one of the few spiders that can easily bite through the 'armor' of a pill bug.
Photography Tips
Focus on the front of the spider to capture the massive fangs and the eye cluster. Indirect lighting is best to avoid glare on its highly glossy cephalothorax.
Identified: 2026-07-02T15:22:01.459096