Cellar Spider, Daddy Long-Legs Spider, Skull Spider
Pholcus phalangioides
Pholcidae (Cellar Spiders), Order Araneae
Physical Description
Characterized by an extremely delicate and fragile appearance with a very small, oval-to-pear-shaped abdomen and a fused cephalothorax. The body structure is lightweight, and the legs are exceptionally long and thread-like, giving it a skeletal or floating look.
Size Estimate
Body length is typically 7 to 10 millimeters, but the massive, thin leg span can easily reach 5 to 7 centimeters.
Coloration & Markings
Pale gray, tan, or yellowish-brown with faint darker markings on the abdomen. The cephalothorax often features a distinct darker central marking that can resemble a skull shape, which inspires one of its common names.
Web Type
Irregular, messy, three-dimensional tangle webs constructed in dark, damp, undisturbed locations such as cellars, basements, and corners of ceilings.
Eye Arrangement
Eight eyes clustered tightly in a triad group on each side of the head region along with a small pair of median eyes, a diagnostic arrangement for the Pholcidae family.
Leg Characteristics
Extremely long, delicate, and wispy legs with high flexibility. When disturbed, the spider vibrates its body rapidly in the web to become a motion blur.
Venom & Safety Information
Venom Information
Contains a mild neurotoxin primarily effective against small arthropod prey. Completely harmless to humans due to small chelicerae.
Medical Significance
No medical significance. Despite the urban legend claiming they possess the most potent venom, their chelicerae cannot pierce human skin.
Safety Recommendations
No safety measures needed as they are completely harmless. They can be left alone for natural pest control or gently relocated using a cup and card.
Habitat & Behavior
Habitat & Range
Cosmopolitan distribution worldwide, predominantly found indoors in human dwellings, garages, sheds, and naturally in caves, rock crevices, and under loose bark.
Behavior & Temperament
Timid and non-aggressive. When threatened, instead of fleeing, they employ a frantic vibrating defense mechanism to confuse predators.
Diet & Prey
Insects and other spiders, including much larger and potentially dangerous species like venomous widows and hobo spiders, which they successfully subdue using silk wraps.
Seasonal Activity
Active year-round indoors due to climate-controlled environments, though reproduction and foraging may peak during warmer months.
Description
The cellar spider is a familiar indoor companion, easily recognized by its tiny body and extraordinarily long, spindly legs. Thriving in the quiet corners of homes worldwide, these peaceful arachnids are expert web-weavers and prolific hunters that act as natural pest controllers.
Key Features
Extremely long and thread-like legs, small oval body, irregular tangle web, and the signature high-speed vibration defense behavior.
Similar Species
Harvestmen (Order Opiliones), which are not true spiders and lack a segmented waist, and Pholcus opilionoides.
Life Cycle
Females carry eggs in a loosely bound silk cluster in their mouthparts until hatching. Spiderlings undergo multiple molts over a lifespan that can exceed two years.
Ecological Importance
Serves as an effective biological control agent inside buildings, helping to regulate populations of nuisance insects and other spiders.
Conservation Status
Not evaluated by the IUCN; highly secure and successfully cohabitating with human environments globally.
Interesting Facts
Cellar spiders are famous for hunting and eating larger spiders, including black widows, and despite popular myths, their venom poses zero threat to humans.
Photography Tips
Use macro lenses with a steady tripod or fast shutter speed to capture the delicate leg structure and head markings, ideally against a clean contrasting background.
User Notes
Hi guys I’m just wondering what the spider is
Identified: 2026-09-21T21:04:32.296800