Cellar Spider, Daddy Long-Legs
Pholcus phalangioides
Pholcidae (Cellar Spiders), Order Araneae
Physical Description
Extremely long, delicate legs and a small, oval to cylindrical abdomen. The cephalothorax is typically pale and fused with distinctive dark markings. The overall appearance is fragile and slender.
Size Estimate
Body length around 7-10 mm with a leg span of up to 5-7 cm.
Coloration & Markings
Pale gray, tan, or light brown with translucent qualities. The cephalothorax often features a dark central marking or pattern, and the abdomen may have subtle gray or brown spots.
Web Type
Irregular, loose, three-dimensional tangle webs built in corners, cellars, and dark crevices.
Eye Arrangement
Eight eyes grouped in a distinctive triad pattern on elevated bumps on the carapace, with two small median eyes.
Leg Characteristics
Exceptionly long and thread-like, capable of autotomy (dropping a leg when grabbed) and vibrating rapidly as a defense mechanism.
Venom & Safety Information
Venom Information
Neurotoxic venom tailored for small invertebrate prey; extremely mild to humans and generally incapable of piercing human skin.
Medical Significance
Harmless to humans. Despite urban legends regarding extreme toxicity, they pose zero medical risk.
Safety Recommendations
No safety measures needed as they are entirely harmless. Can be gently relocated using a cup and paper if unwanted.
Habitat & Behavior
Habitat & Range
Cosmopolitan distribution; found globally in human dwellings, damp cellars, garages, caves, and sheltered outdoor locations.
Behavior & Temperament
Docile and non-aggressive. When disturbed, they perform a frantic shaking or vibrating motion to blur their body and confuse predators.
Diet & Prey
Insects and other spiders, famously including larger spiders like venomous widows and funnel-webs which they subdue using silk wrapping techniques.
Seasonal Activity
Active year-round indoors, with peak mating and visibility during the warmer spring and summer months.
Description
The cellar spider is a familiar household guest known for its impossibly delicate legs and erratic vibrating defense. While often overlooked or mistaken for harvestmen, these beneficial arachnids act as quiet guardians against household pests and other spiders.
Key Features
Extremely long, thin legs, pale translucent body, irregular tangle web, and the characteristic rapid vibrating response when disturbed.
Similar Species
Opiliones (Harvestmen, which lack a segmented waist and silk glands) and Pholcus opilionoides.
Life Cycle
Females carry eggs in a loose silk sac held in their jaws. Spiderlings hatch and undergo several molts before reaching maturity, living up to several years.
Ecological Importance
Serves as an effective natural pest controller in homes and buildings, keeping populations of flies, mosquitoes, and other spiders in check.
Conservation Status
Not evaluated by the IUCN, highly secure and abundant globally due to close association with human habitations.
Interesting Facts
Despite the urban legend that they are the most venomous spiders with mouths too small to bite humans, scientific testing has proven their venom is very weak against mammals and their chelicerae can easily pierce thin human skin, though they rarely do so.
Photography Tips
Use macro lenses with diffused lighting to capture the delicate leg details and eye arrangement without causing the spider to vibrate away.
Identified: 2026-09-06T04:37:59.476186