Cellar Spider, Daddy Long-Legs Spider, Skull Spider
Pholcus phalangioides
Pholcidae (Cellar Spiders), Order Araneae
Physical Description
Small, delicate body with long, extremely thin legs. The cephalothorax is short and wide, and the abdomen is typically cylindrical or oval, sometimes elongated, giving it a distinctive shape. They have a fragile, smooth appearance.
Size Estimate
Body length ranges from 7 to 10 mm, with a leg span reaching up to 50 to 70 mm. This appears to be an adult specimen.
Coloration & Markings
Pale, translucent greyish-yellow or whitish color, sometimes with darker grey or brown markings on the cephalothorax and abdomen.
Web Type
Irregular, tangled cobweb built in corners, cellars, and dark, undisturbed spaces. They do not use sticky silk; instead, their webs form a chaotic mesh that entangles prey.
Eye Arrangement
Eight eyes arranged in two lateral triads and a pair of smaller median eyes situated close together on a raised bump.
Leg Characteristics
Extremely long, thin, and fragile legs lacking strong spines. They often bounce rapidly in their web when disturbed as a defensive display.
Venom & Safety Information
Venom Information
Neurotoxic venom tailored for small invertebrate prey. Extremely weak relative to humans and generally incapable of penetrating human skin.
Medical Significance
Harmless to humans. Despite urban legends regarding extreme toxicity, they pose zero medical danger and cannot effectively bite humans.
Safety Recommendations
No safety measures needed as they are completely harmless. They can be safely left alone to control pests or gently relocated using a cup and card.
Habitat & Behavior
Habitat & Range
Cosmopolitan distribution worldwide, predominantly found indoors in cellars, garages, basements, and dark corners of buildings, as well as sheltered outdoor locations.
Behavior & Temperament
Docile, sedentary, and non-aggressive. When threatened, they vigorously vibrate their webs to blur their image and confuse predators.
Diet & Prey
Insects and other spiders, including larger spiders like venomous widows. They subdue prey by throwing silk over them from a safe distance using their long legs.
Seasonal Activity
Active year-round indoors, with increased movement and mating activity typically observed during warmer spring and summer months.
Description
The cellar spider is a familiar and harmless household resident, recognizable by its incredibly long, spindly legs and delicate pale body. Often found hanging upside down in chaotic webs in dark corners, these master pest controllers quietly manage populations of household insects and even other spiders.
Key Features
Extremely long and thin legs, pale translucent coloration, cylindrical abdomen, and the distinct habit of vibrating rapidly when disturbed.
Similar Species
Harvestmen (Order Opiliones, also called daddy long-legs), which are not true spiders, lack silk glands, and possess a fused, single body segment instead of two.
Life Cycle
Females carry eggs in a loose silk cluster held in their chelicerae until hatching. Spiderlings undergo several molts to reach adulthood, with a typical lifespan of up to two to three years.
Ecological Importance
Act as effective biological control agents in human habitations, suppressing populations of nuisance insects, flies, and other arachnids.
Conservation Status
Not evaluated by the IUCN, but highly secure and thriving globally due to close association with human dwellings.
Interesting Facts
Cellar spiders are famous for hunting and defeating larger, medically significant spiders such as redback spiders and black widows by wrapping them in silk before biting.
Photography Tips
Use a macro lens with a soft fill-light or ring flash to highlight the delicate leg structures and eye arrangement while maintaining a steady position to avoid camera shake.
Identified: 2026-08-23T14:42:49.761179