Cellar Spider, Daddy Long-Legs Spider, Skull Spider
Pholcus phalangioides
Family Pholcidae (Cellar Spiders), Order Araneae. Key family characteristics include long, delicate legs and an ability to vibrate rapidly when disturbed.
Physical Description
Small, pale body with an elongated, cylindrical abdomen and a short, broad cephalothorax. The proportions feature exceptionally long, spindly legs relative to the tiny body. The overall texture is smooth and matte with minimal noticeable hair.
Size Estimate
Body length ranges from 7 to 10 millimeters, with a total leg span reaching up to 5 to 7 centimeters. This specimen appears to be an adult.
Coloration & Markings
Pale yellow, grey, or translucent tan overall. The cephalothorax often features a faint darker marking, sometimes described as a violin shape or a vague smudge, and the abdomen is uniformly pale without prominent patterns.
Web Type
Irregular, loose 3D tangle webs or cobwebs constructed in corners, ceilings, cellars, and dark crevices. The webs do not use sticky silk; instead, prey becomes hopelessly entangled in the chaotic mesh.
Eye Arrangement
Eight eyes arranged in three groups: a triad on each side and a pair of smaller median eyes closely set on a raised tubercle on the front of the cephalothorax.
Leg Characteristics
Extremely long, thin, thread-like legs with subtle pale banding. They lack heavy spination. When threatened, the spider rapidly vibrates its body in the web to become a blur, making it difficult for predators to target.
Venom & Safety Information
Venom Information
Neurotoxic venom tailored specifically for small arthropods and insects. It is extremely weak against human skin and poses no threat.
Medical Significance
Harmless to humans. Urban legends claiming they possess deadly venom with jaws too small to bite humans are completely false; their chelicerae can barely pierce human skin, and the venom has negligible effect.
Safety Recommendations
No safety measures are necessary as they are completely harmless. If desired, they can be gently relocated outside using a cup and a piece of paper.
Habitat & Behavior
Habitat & Range
Cosmopolitan distribution across temperate and tropical regions worldwide. Prefers dark, humid, undisturbed indoor environments such as cellars, basements, garages, crawl spaces, and corners of rooms.
Behavior & Temperament
Non-aggressive and docile. They are nocturnal hunters that sit upside down in their webs. When disturbed, they perform a rapid vibrating or bouncing defense motion.
Diet & Prey
Generalist predators feeding on various crawling and flying insects, other spiders (including venomous species like widow spiders), and small arthropods captured in their web.
Seasonal Activity
Active year-round indoors where temperatures remain stable, with increased mobility and mating activity typically observed during warmer spring and summer months.
Description
The cellar spider is a familiar and harmless household companion across the globe. Recognizable by its remarkably long, delicate legs and small pale body, it hangs unobtrusively in dark corners. Though often mistaken for harvestmen, true cellar spiders are skilled predators that help keep homes free of pest insects and even other, more troublesome spiders.
Key Features
Extremely long and spindly legs, pale translucent body, elongated cylindrical abdomen, and the distinct habit of vibrating rapidly when disturbed in its irregular web.
Similar Species
Harvestmen (Order Opiliones, commonly called daddy long-legs) which are not true spiders and lack a segmented waist; Pholcids can be distinguished by their two distinct body segments.
Life Cycle
Females produce loose silk egg sacs containing around 20 to 60 eggs, which they carry around in their jaws until hatching. Spiderlings undergo several molts to reach adulthood, with a total lifespan lasting up to several years.
Ecological Importance
Serves as an effective natural pest control agent within human habitations and natural crevices, regulating populations of flies, mosquitoes, and other insects.
Conservation Status
Not evaluated by the IUCN, but highly secure and thriving globally due to its close association with human dwellings.
Interesting Facts
Cellar spiders are known to actively hunt and consume other spiders, including much larger species like funnel-web spiders and redback spiders, using their long legs to wrap prey from a safe distance.
Photography Tips
Use a macro lens with a soft, diffused flash to capture the fine details of the eye arrangement and leg joints. Photographing from the side against a neutral background yields the best identification shots.
Identified: 2026-08-06T22:59:47.415319