Cellar Spider, Daddy Long-Legs Spider, Skull Spider
Pholcus phalangioides
Family Pholcidae (Cellar Spiders), Order Araneae. Key family characteristics include extremely long, delicate legs and an oval or elongated abdomen.
Physical Description
Small, oval-shaped body with a distinctively small cephalothorax and a longer, cylindrical abdomen. The spider has very slender, delicate proportions with a smooth cuticle and no prominent hairs.
Size Estimate
Body length is approximately 7 to 10 millimeters, with an expansive leg span reaching up to 5 to 7 centimeters. This appears to be an adult specimen.
Coloration & Markings
Pale yellowish-grey to light tan coloration overall. The cephalothorax often features a darker grey or brown marking near the center, sometimes resembling a subtle skull pattern.
Web Type
Irregular, sticky tangle webs (cobwebs) constructed in dark, damp corners, basements, and around sinks or ceilings.
Eye Arrangement
Eight eyes grouped closely together on an elevated hump on the cephalothorax, consisting of a triad on each side and a pair of smaller median eyes.
Leg Characteristics
Extremely long, thread-like, and fragile legs with very fine spination. They lack specialized heavy claw tufts and typically rest flat against surfaces or suspended in their web.
Venom & Safety Information
Venom Information
Neurotoxic venom designed specifically for small invertebrate prey. Their chelicerae are very small and generally unable to effectively pierce human skin.
Medical Significance
Harmless to humans. Despite urban legends regarding extreme toxicity, they pose zero medical significance and are incapable of delivering a clinically relevant bite to humans.
Safety Recommendations
No safety measures needed as they are completely harmless. If relocation is desired, gently cup the spider in a container and release it outside or in a sheltered outbuilding.
Habitat & Behavior
Habitat & Range
Cosmopolitan distribution worldwide, primarily synanthropic, living indoors in human structures such as cellars, garages, basements, and bathrooms.
Behavior & Temperament
Docile and non-aggressive. When disturbed, they perform a rapid vibratory or bouncing motion in their web to blur their image and confuse predators.
Diet & Prey
Generalist predator feeding on insects, other spiders (including venomous species like widow spiders), and occasionally small crawling arthropods caught in their webs.
Seasonal Activity
Active year-round indoors where temperature and humidity are stable, though mating and reproduction often peak during warmer spring and summer months.
Description
The cellar spider is a familiar and harmless indoor companion, easily recognized by its exceptionally long, spindly legs and delicate body. Often found hanging upside down in dark corners or bathroom sinks, these master web-weavers play a beneficial role in residential pest control by subduing other household bugs and even dangerous spiders.
Key Features
Extremely long and fragile legs, pale translucent tan body, small cephalothorax with an elevated eye tubercle, and the signature defensive bouncing behavior when disturbed.
Similar Species
Often confused with harvestmen (Opiliones, which are not true spiders and lack silk glands and a constricted waist) and cellar-dwelling spitting spiders (Scytodidae), which have a more rounded, patterned carapace.
Life Cycle
Females carry eggs in a loose, silk-wrapped cluster held directly in their jaws until hatching. Spiderlings undergo several molts to reach maturity, with a total lifespan lasting up to several years.
Ecological Importance
Acts as an effective natural pest controller in human dwellings, keeping populations of flies, mosquitoes, and other spiders in check.
Conservation Status
Not evaluated by the IUCN, but populations are secure, abundant, and globally widespread due to their close association with human habitations.
Interesting Facts
Cellar spiders are famous for hunting and consuming other spiders, including much larger and potentially dangerous species like black widows. The urban legend that they possess the most potent venom in the world is entirely false.
Photography Tips
Use macro lenses with good depth of field to capture the entire leg span. Shoot from the side or slightly above in soft, diffused lighting to highlight the delicate leg structure and eye tubercles.
Identified: 2026-09-18T06:55:53.384410