Cellar Spider, Daddy Long-Legs Spider, Skull Spider
Pholcus phalangioides
Family Pholcidae (Cellar Spiders), Order Araneae. Key family characteristics include extremely long, delicate legs and an often elongated or oval abdomen.
Physical Description
The spider features an extremely slender, delicate body with an elongated, cylindrical abdomen and a small, distinct cephalothorax. The overall appearance is fragile, with a smooth exoskeleton and remarkably long, thread-like legs.
Size Estimate
Body length is typically around 7-10 mm, with a massive leg span reaching up to 5-7 cm. This specimen appears to be an adult.
Coloration & Markings
Pale gray, tan, or light brown overall, often translucent. The cephalothorax typically features a darker, characteristic marking that sometimes resembles a faint skull pattern, and the abdomen may have subtle grayish spots or chevrons.
Web Type
Irregular, loose 3D tangle webs (cobwebs) constructed in dark, humid corners, basements, and ceilings. These webs are not sticky in the traditional sense; instead, they rely on a tangled mesh that entangles the feet of walking insects.
Eye Arrangement
Eight eyes clustered tightly on an elevated portion of the cephalothorax, consisting of a triad on each side and a pair of smaller median eyes.
Leg Characteristics
Legs are exceptionally long, thin, and fragile with subtle darker banding. When disturbed, the spider performs a rapid vertical vibrating or bouncing motion in its web to blur its image and confuse predators.
Venom & Safety Information
Venom Information
Contains mild neurotoxic venom tailored specifically for small arthropods and insects.
Medical Significance
Completely harmless to humans. Their chelicerae are generally too weak or short to puncture human skin, and even if they do, the venom has no significant medical effect.
Safety Recommendations
No safety measures needed as they are completely harmless. If unwanted, they can be gently relocated outside using a cup and a piece of paper.
Habitat & Behavior
Habitat & Range
Cosmopolitan distribution worldwide. Highly synanthropic, preferring indoor environments such as dark corners of cellars, basements, garages, crawlspaces, and upper corners of rooms.
Behavior & Temperament
Dull and sedentary, spending most of its time hanging upside down in its web. Completely non-aggressive toward humans, retreating or vibrating when disturbed.
Diet & Prey
Feeds on a wide variety of small insects and other spiders, famously including larger spiders such as funnel-web spiders and widows, which it wraps rapidly with silk from a distance.
Seasonal Activity
Active year-round indoors due to climate-controlled environments, though mating peaks during warmer months.
Description
The cellar spider is a familiar and harmless household resident, easily recognized by its tiny body and ridiculously long, spindly legs. Hanging effortlessly in dusty corners, it acts as a silent guardian against household pests and even other, more formidable spiders.
Key Features
Extremely long, thread-like legs; pale, translucent, slightly elongated abdomen; habit of rapidly vibrating when disturbed; construction of messy tangle webs in indoor corners.
Similar Species
Harvestmen (Order Opiliones, true daddy long-legs), which are not true spiders and lack a divided two-part body and silk glands; Pholcidae can be distinguished by their pinched waist and distinct cephalothorax/abdomen split.
Life Cycle
Females carry their pale, loosely-webbed egg masses in their jaws until the spiderlings hatch. Juveniles undergo multiple molts before reaching maturity, with a total lifespan often spanning a few years.
Ecological Importance
Serves as an effective natural pest control agent inside homes, reducing populations of mosquitoes, flies, and other nuisance insects, and occasionally keeping venomous spider populations in check.
Conservation Status
Not evaluated by the IUCN, but highly secure and thriving globally due to close association with human habitations.
Interesting Facts
Despite an urban legend claiming they are the most venomous spiders with mouths too small to bite humans, this is entirely false; their venom is very weak to vertebrates, and they can occasionally bite humans, though the effect is negligible.
Photography Tips
Use a macro lens with a shallow depth of field to isolate the spider from the background wall. Side lighting helps highlight the delicate structure of the legs and the translucent body.
Identified: 2026-08-26T22:04:10.232650