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 cylindrical abdomen.
Physical Description
The spider has a small, pale, pear-shaped or cylindrical cephalothorax and a longer, slender, grayish-yellow abdomen. Its most distinctive features are its disproportionately long, thin legs relative to its tiny body.
Size Estimate
Body length is typically around 7-10 mm, with a leg span reaching up to 5-7 cm. The specimen appears to be an adult.
Coloration & Markings
Pale gray, tan, or yellowish overall, sometimes with darker gray markings or spots on the cephalothorax and abdomen. The cephalothorax often features a dark, somewhat characteristic pattern resembling a skull.
Web Type
Builds irregular, messy, three-dimensional tangle webs or space webs in corners of ceilings, walls, or cellars using non-sticky silk.
Eye Arrangement
Eight eyes grouped closely together on an elevated hump on the cephalothorax, consisting of a triad on each side and two smaller median eyes.
Leg Characteristics
Extremely long, thin, fragile legs with flexible tarsi that vibrate rapidly when disturbed to blur the spider's outline from predators.
Venom & Safety Information
Venom Information
Contains a mild neurotoxic venom designed specifically for small invertebrate prey. It poses no threat to humans.
Medical Significance
Harmless to humans. Its chelicerae are generally too weak or short to puncture human skin, and the venom has no significant medical impact.
Safety Recommendations
No safety measures are necessary as they are harmless. If unwanted, they can be gently relocated outside using a cup and a piece of paper.
Habitat & Behavior
Habitat & Range
Cosmopolitan distribution worldwide. Prefers dark, damp, protected indoor microhabitats such as basements, cellars, crawlspaces, and corners of rooms.
Behavior & Temperament
Docile and completely non-aggressive toward humans. When disturbed, it vigorously bounces or vibrates in its web to avoid detection.
Diet & Prey
Feeds on a variety of insects and other spiders, famously including venomous species like widow spiders and hobo spiders, which it wraps in silk at a distance.
Seasonal Activity
Active year-round indoors where temperatures are stable, with reproduction often occurring throughout the warmer months.
Description
Pholcus phalangioides, commonly known as the cellar spider, is a ubiquitous indoor dweller famous for its extremely long legs and delicate build. Often mistaken for harvestmen, these master architects spin tangled webs in neglected corners and act as diligent household pest controllers.
Key Features
Extremely long and thin legs, tiny pale body, tendency to vibrate rapidly when disturbed, and preference for ceiling or wall corners indoors.
Similar Species
Opiliones (Harvestmen or Daddy Long-Legs), which are arachnids but not true spiders (losing the distinct two-body-segment division and silk glands).
Life Cycle
Females carry eggs in a loose, silk-bound cluster held directly in their jaws until hatching. Spiderlings undergo several molts to reach adulthood, living up to several years.
Ecological Importance
Serves as an effective biological control agent inside human dwellings, significantly reducing populations of nuisance insects and other spiders.
Conservation Status
Not evaluated by the IUCN, but populations are secure, abundant, and widely distributed globally due to human association.
Interesting Facts
Cellar spiders are renowned for hunting and defeating much larger, medically significant spiders such as black widows by expertly throwing silk over them.
Photography Tips
Use a macro lens with good side lighting to highlight the delicate leg structure and the subtle markings on the tiny cephalothorax.
Identified: 2026-10-19T01:57:59.382996