Cellar Spider, Daddy Long-Legs Spider
Pholcus phalangioides
Pholcidae (Cellar Spiders), Order Araneae
Physical Description
Small, oval-shaped abdomen with a fused or distinct cephalothorax, extremely long and delicate legs, and a fragile overall appearance.
Size Estimate
Body length around 7 to 10 mm with a leg span reaching up to 5 to 7 cm.
Coloration & Markings
Pale, translucent greyish-brown or yellowish color, often with faint darker markings or spots on the carapace and abdomen.
Web Type
Irregular, loose 3D tangle web (cobweb) constructed in corners of ceilings, walls, cellars, or dark damp spaces.
Eye Arrangement
Eight eyes arranged in a prominent cluster consisting of a central triad and two lateral dyads.
Leg Characteristics
Exceptionally long, thin, thread-like legs with subtle dark banding, lacking heavy spination, capable of a rapid shaking or vibrating defense mechanism.
Venom & Safety Information
Venom Information
Mild venom designed primarily for small invertebrate prey; largely ineffective against human skin.
Medical Significance
Harmless to humans. Despite an old urban legend regarding extreme toxicity, their mouthparts are generally too small or weak to pierce human skin, and the venom is weak.
Safety Recommendations
Completely safe to leave alone as natural pest control. Can be gently relocated using a container and a piece of paper if found in an undesired location.
Habitat & Behavior
Habitat & Range
Cosmopolitan distribution globally; strongly synanthropic, preferring dark, humid indoor areas like cellars, basements, and upper corners of rooms.
Behavior & Temperament
Docile and non-aggressive; when disturbed, rapidly vibrates its web to become a blur to confuse predators.
Diet & Prey
Insects and other spiders, famously including larger spiders like black widows and hobo spiders, which they wrap in silk before biting.
Seasonal Activity
Active year-round indoors due to climate-controlled environments, with mating occurring during warmer months.
Description
The cellar spider is a familiar and harmless indoor resident, easily recognized by its exceptionally long, delicate legs and preference for hanging upside down in ceiling corners. While often mistaken for harvestmen, they are true spiders that play a beneficial role in controlling household pests.
Key Features
Extremely long, fragile legs, pale coloration, irregular tangle web in indoor corners, and the rapid-vibration defensive behavior.
Similar Species
Harvestmen (Order Opiliones), which are arachnids but not true spiders, and have a single fused body segment and lack silk glands.
Life Cycle
Females carry eggs loosely bundled in their chelicerae until hatching. Juveniles molt multiple times before reaching adulthood, with a typical lifespan of up to two to three years.
Ecological Importance
Acts as a natural pest controller inside buildings, helping to suppress populations of flies, mosquitoes, and other household insects.
Conservation Status
Not evaluated by the IUCN, but highly secure and widespread globally due to human commensalism.
Interesting Facts
Cellar spiders are notorious for hunting and consuming other formidable spiders, including venomous widows, by using long legs to keep dangerous prey at a safe distance while throwing silk.
Photography Tips
Use macro lighting or a flashlight to illuminate the translucent body against dark ceiling corners, focusing on the eye arrangement and leg joints for clear identification.
User Notes
On my ceiling
Identified: 2026-08-28T19:15:57.548221