Cellar Spider, Daddy Long-Legs Spider, Skull Spider
Pholcus phalangioides
Pholcidae (Cellar Spiders), Order Araneae. Key family characteristics include extremely long, delicate legs and an oval or fused carapace region.
Physical Description
The spider has a small, oval-to-cylindrical abdomen and a compact, somewhat fused cephalothorax that often features a dark, distinctive marking. The overall build is extremely delicate, with extremely slender limbs and a translucent, glossy appearance.
Size Estimate
Body length is roughly 7 to 10 millimeters, while the leg span is dramatically wider, typically reaching 5 to 7 centimeters. This specimen appears to be a fully grown adult.
Coloration & Markings
Pale gray, tan, or yellowish-brown base coloration. The cephalothorax often displays a darker central marking or pattern, while the abdomen may have faint greyish spots or banding, though it is mostly uniform.
Web Type
Irregular, loose 3D tangle webs or sheet-like cobwebs built in corners, basements, and dark crevices. The web is non-sticky and meant to trap and entangle wandering insects.
Eye Arrangement
Eight eyes arranged in three groups: a triad on each side and a pair of smaller median eyes, situated on a slightly raised eye turret on the cephalothorax.
Leg Characteristics
Extremely long, thread-like, and fragile legs with slight darker banding at the joints. They lack heavy spination and are designed to vibrate rapidly when threatened.
Venom & Safety Information
Venom Information
Contains neurotoxic venom tailored for small arthropods. Its chelicerae are extremely weak and generally incapable of piercing human skin, making it virtually harmless to people.
Medical Significance
Not medically significant. Bites are extremely rare and virtually impossible due to mouthpart limitations; if a bite were to occur, symptoms are negligible, akin to a mild pinprick.
Safety Recommendations
No safety measures are required 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 dark, humid indoor areas such as cellars, basements, crawlspaces, garages, and corners of ceilings.
Behavior & Temperament
Docile and completely harmless to humans. When disturbed, it employs a signature defensive strategy: violently vibrating its body in the web to become a blur and evade predators.
Diet & Prey
Generalist carnivore feeding on small insects, other spiders (including venomous species like redbacks or widows), and crawling pests found around houses.
Seasonal Activity
Active year-round indoors, as they benefit from climate-controlled human habitations, though mating and reproductive activity often peak during warmer months.
Description
The cellar spider is a familiar yet misunderstood household resident. Known commonly as the daddy long-legs spider, its paper-thin body and impossibly long limbs make it appear fragile, yet it is a remarkably effective predator capable of subduing much larger spiders.
Key Features
Extremely long and slender legs, small oval abdomen, pale translucent body, and the characteristic rapid-vibration defense mechanism when disturbed.
Similar Species
Often confused with harvestmen (Opiliones, which are arachnids but not true spiders) and cellar-dwelling spitting spiders (Scytododes), which have distinct spotted patterns and different eye arrangements.
Life Cycle
Females carry eggs in a loose silk cluster held in their jaws rather than building a stationary egg sac. Spiderlings hatch and undergo multiple molts before reaching maturity, with a total lifespan of up to several years.
Ecological Importance
Serves as an effective natural pest control agent inside buildings by keeping populations of flies, mosquitoes, and other spiders in check.
Conservation Status
Not evaluated by the IUCN, but highly secure and widespread globally due to its close association with human structures.
Interesting Facts
Cellar spiders are famous urban legends regarding extreme venom toxicity; however, science has proven this completely false. They are also known for actively hunting and consuming dangerous widow spiders.
Photography Tips
Use a macro lens with good side lighting to highlight the delicate leg structure and eye arrangement. Photographing against a neutral background helps isolate the subject.
Identified: 2026-08-23T17:42:35.569091