Long-bodied Cellar Spider, Daddy Long-legs Spider, Skull Spider
Pholcus phalangioides
Family Pholcidae (Cellar Spiders), Order Araneae. Key family characteristics include exceptionally long, delicate legs and an oval or elongated abdomen.
Physical Description
The spider has a small, oval abdomen, a somewhat rounded cephalothorax, and extremely long, thin legs relative to its body size. The texture is smooth with fine, sparse hairs. It has no distinct sexual dimorphism in shape, though males possess enlarged pedipalps.
Size Estimate
Body length ranges from 7 to 10 millimeters, with a leg span reaching up to 5 to 7 centimeters. This specimen appears to be an adult.
Coloration & Markings
Pale grayish-yellow to light brown, often featuring darker grey or brown markings on the cephalothorax, including a distinct dark spot or pattern that resembles a skull shape when viewed from above.
Web Type
Irregular, loose 3D tangle webs or cobwebs constructed in corners of rooms, cellars, or dark structural spaces. These webs are non-sticky and trap prey through sheer structural complexity.
Eye Arrangement
Six eyes arranged in two lateral triads and a dyad in the middle (though some pholcids have eight, Pholcus typically has six distinct eyes set closely together on an elevated cephalothorax region).
Leg Characteristics
Extremely long, thin, fragile legs with no strong spines. When disturbed, the spider can rapidly vibrate its entire body in the web to blur its outline, a defense mechanism known as 'gyrating'.
Venom & Safety Information
Venom Information
Contains a mild neurotoxin primarily effective against small insect prey. Its chelicerae are theoretically capable of piercing human skin, but envenomation is extremely rare and causes negligible local effects.
Medical Significance
Harmless to humans. Despite urban legends regarding extreme toxicity, they pose zero medical threat and cannot cause systemic harm to people.
Safety Recommendations
No special safety precautions are 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, heavily associated with human habitations, basements, cellars, caves, and dark, undisturbed corners of buildings.
Behavior & Temperament
Docile and non-aggressive. When approached or threatened, it vigorously vibrates in its web to avoid detection or drops down to escape.
Diet & Prey
Insects and other spiders, including medically significant species like the redback or hobo spider, which it actively wraps and subdues using rapid silk-throwing techniques.
Seasonal Activity
Active year-round indoors where climate is controlled, though mating and peak activity often align with warmer spring and summer months.
Description
Commonly known as the daddy long-legs, Pholcus phalangioides is a master of indoor survival. With its impossibly slender legs and unassuming web in the corner of a ceiling, it acts as a silent and efficient guardian against household pests.
Key Features
Extremely long and spindly legs, pale translucent-brown coloration, distinct dark cephalothorax markings, and the signature web-vibrating defensive behavior.
Similar Species
Harvestmen (Order Opiliones, also called daddy long-legs) which are not true spiders and lack a constricted waist; cellar spiders of other genera such as Psilochorus.
Life Cycle
Females carry eggs in a loose silk cluster held in their chelicerae rather than spinning a fixed egg sac. Spiderlings hatch and disperse locally, undergoing multiple molts to reach maturity over a year.
Ecological Importance
Serves as an effective biological control agent inside buildings by preying on nuisance insects, flies, mosquitoes, and other potentially problematic spiders.
Conservation Status
Not evaluated by the IUCN, highly secure and thriving globally due to close association with human dwellings.
Interesting Facts
Despite a persistent urban myth claiming they possess the most potent venom of any spider but lack fangs strong enough to deliver it, scientific studies have shown their venom has very low toxicity to mammals.
Photography Tips
Use a macro lens with a shallow depth of field. Photograph from the side to capture the delicate leg proportions, and use indirect lighting to highlight the translucent body details without causing harsh shadows.
Identified: 2026-08-09T21:45:06.370911