Cellar Spider, Daddy Long-Legs Spider, Skull Spider
Pholcus phalangioides
Family Pholcidae, Order Araneae. Characterized by extremely long, delicate legs and a small, oval or cylindrical abdomen.
Physical Description
Small, fragile-looking spider with a pear-shaped cephalothorax and an elongated, cylindrical abdomen. The cephalothorax often features a dark, somewhat skull-like marking in some species, though overall the body appears pale and translucent.
Size Estimate
Body length is typically around 7 to 10 millimeters, with a very expansive leg span reaching up to 5 centimeters or more.
Coloration & Markings
Pale gray, yellowish-tan, or whitish coloration with faint darker markings on the abdomen and legs. The body is often semi-translucent, blending well into indoor corners.
Web Type
Irregular, tangled web (cobweb) constructed in dark, quiet corners, basements, or ceilings. These webs are not sticky in the traditional sense; instead, they rely on tangled silk threads to entrap prey.
Eye Arrangement
Eight eyes arranged in a unique triad formation: a tight cluster of three eyes on each side and a pair of smaller median eyes, typical of the Pholcidae family.
Leg Characteristics
Extremely long, thin, thread-like legs that lack spines but possess remarkable flexibility. When disturbed, the spider engages in a rapid vibrating or bouncing defense mechanism.
Venom & Safety Information
Venom Information
Contains neurotoxic venom tailored specifically for invertebrate prey. Although widely rumored to be dangerously venomous with ineffective fangs, they are entirely harmless to humans.
Medical Significance
Negligible. Their chelicerae are generally too small or weak to puncture human skin, and their venom poses no threat to humans or pets.
Safety Recommendations
No safety measures needed as they are completely harmless. If unwanted, gently relocate them using a cup and a piece of paper.
Habitat & Behavior
Habitat & Range
Cosmopolitan distribution found worldwide, particularly associated with human habitations, cellars, crawlspaces, garages, caves, and dark, undisturbed indoor corners.
Behavior & Temperament
Docile and non-aggressive. When threatened, it violently shakes its web to blur its image and evade predators, or drops from the web entirely.
Diet & Prey
Generalist predator feeding on small insects, other spiders (including venomous species like widow spiders), and occasionally crawling pests found around homes.
Seasonal Activity
Active year-round indoors due to climate-controlled environments, though mating and reproduction often peak during the warmer months.
Description
The cellar spider is a familiar and harmless indoor companion, easily recognized by its exceptionally delicate frame and long legs. Preferring the quiet corners of ceilings and basements, it serves as a silent and efficient household predator.
Key Features
Extremely long and thin legs, pale translucent body, cylindrical abdomen, and the distinct habit of vibrating rapidly when disturbed.
Similar Species
Harvestmen (Order Opiliones), which are arachnids but not true spiders; they lack a segmented waist and silk glands. Also confused with spitting spiders (Scytodidae).
Life Cycle
Females carry eggs in a loose silk cluster held tightly in their jaws until hatching. Spiderlings undergo multiple molts, and adults can live for several years in stable indoor environments.
Ecological Importance
Acts as an effective natural pest controller in human dwellings, regulating populations of flies, mosquitoes, and other household insects.
Conservation Status
Not evaluated by the IUCN, but highly secure and ubiquitous globally due to its close association with human structures.
Interesting Facts
Cellar spiders are renowned for hunting and defeating larger, potentially dangerous spiders such as widows and funnel-weavers by wrapping them in silk from a safe distance.
Photography Tips
Use macro settings with a stable surface or tripod. Focus on the cephalothorax and eye pattern, and capture the spider in its natural web context with soft lighting.
Identified: 2026-08-23T11:00:50.330498