Cellar Spider, Daddy Long-Legs Spider, Skull Spider
Pholcus phalangioides
Family Pholcidae (Cellar Spiders), Order Araneae. Key family characteristics include long, delicate legs and an often oval or cylindrical abdomen.
Physical Description
The spider has a very small, rounded cephalothorax and an elongated, cylindrical abdomen. It has extremely thin, delicate proportions with long, whip-like legs relative to its tiny body size.
Size Estimate
Body length is typically around 7-10 mm, with a leg span reaching up to 5-7 cm. This specimen appears to be an adult.
Coloration & Markings
Pale grayish-yellow to translucent tan with a darker, faint marking on the carapace that sometimes resembles a human skull or violin shape, leading to occasional confusion.
Web Type
Irregular, messy tangle webs built in dark, damp corners, cellars, basements, and ceilings. They lack sticky lines and instead rely on entangling prey.
Eye Arrangement
Six eyes arranged in two triads on the elevated head region, plus a smaller pair in the middle, typical of the Pholcidae family.
Leg Characteristics
Extremely long, thin, and fragile legs with dark banding at the joints. They are capable of vibrating rapidly when disturbed as a defense mechanism.
Venom & Safety Information
Venom Information
Neurotoxic venom specialized for arthropod prey. Completely harmless to humans as their fangs are too small and weak to effectively pierce human skin.
Medical Significance
Negligible to none. They are completely harmless to humans and are considered beneficial household guests.
Safety Recommendations
No safety measures needed as they are completely harmless. If unwanted, they can be gently relocated using a cup and a piece of paper.
Habitat & Behavior
Habitat & Range
Cosmopolitan distribution worldwide, heavily synanthropic. Found primarily indoors in cellars, basements, garages, and dark corners of buildings, as well as caves and under rock ledges outdoors.
Behavior & Temperament
Docile and non-aggressive. When threatened, they vigorously vibrate their bodies in their webs to become a blur and confuse predators, or drop from the web entirely.
Diet & Prey
Generalist predators consuming small insects, other spiders (including medically significant species like widow spiders), and occasionally crawling pests.
Seasonal Activity
Active year-round indoors due to climate-controlled environments, with increased wandering and mating activity peaking during the autumn months.
Description
The cellar spider is a familiar and harmless household resident, easily recognized by its exceptionally long legs and fragile body. Often found dangling upside down in dark corners, these master web-weavers play an important role in controlling indoor insect populations.
Key Features
Extremely long, thin legs, elongated grayish abdomen, distinctive rapid vibration behavior when disturbed, and lack of sticky orb webs.
Similar Species
Opiliones (Harvestmen, which are arachnids but not true spiders and lack a segmented waist) and cellar-dwelling spitting spiders (Scytodidae), which have a more domed cephalothorax.
Life Cycle
Females carry eggs in a loose silk cluster held in their chelicerae until hatching. Spiderlings undergo several molts to reach adulthood, living up to 2-3 years.
Ecological Importance
Serves as an effective natural pest controller in homes and buildings, helping to keep populations of flies, mosquitoes, and other spiders in check.
Conservation Status
Not evaluated by the IUCN, highly stable and widespread globally due to close association with human habitations.
Interesting Facts
Despite an old urban legend claiming they are the most venomous spiders with mouths too small to bite humans, this is entirely false; their venom is mild and they pose zero threat to people.
Photography Tips
Use macro lenses with a high depth of field to capture both the tiny body and the long legs. Shoot from the side with soft, diffused lighting to highlight the translucent texture.
Identified: 2026-08-26T02:25:03.455854