Cellar Spider, Daddy Long-Legs
Pholcus phalangioides
Pholcidae (Cellar Spiders), Order Araneae. Key family characteristics include extremely long, delicate legs and an oval or elongated abdomen.
Physical Description
The spider has a small, pale, pear-shaped cephalothorax and an elongated, cylindrical abdomen. It appears delicate with slender body proportions.
Size Estimate
Body length is typically around 7 to 10 millimeters, with a leg span reaching up to 5 to 7 centimeters.
Coloration & Markings
Pale gray, tan, or yellowish with faint darker markings on the cephalothorax and abdomen.
Web Type
Irregular, tangled space webs (cobwebs) constructed in dark, damp corners, cellars, and 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, thin, thread-like legs without prominent spines, capable of vibrating rapidly when disturbed as a defense mechanism.
Venom & Safety Information
Venom Information
Envenomation is generally ineffective against humans due to small fangs and weak venom, though it is used effectively to subdue small invertebrate prey.
Medical Significance
Harmless to humans. Despite urban legends regarding extreme toxicity, their fangs are rarely able to pierce human skin, and the venom has negligible effect on humans.
Safety Recommendations
No special precautions needed. They are beneficial and harmless; if unwanted, they can be gently relocated outside using a cup and a piece of paper.
Habitat & Behavior
Habitat & Range
Cosmopolitan distribution worldwide; commonly found indoors in dark corners, cellars, basements, and around human habitations, as well as caves and under rock ledges outdoors.
Behavior & Temperament
Docile and entirely harmless to humans. When disturbed, it shakes its web violently to become a blur and evade predators.
Diet & Prey
Insects and other spiders, including medically significant species like widow spiders, which it catches by wrapping them rapidly with silk.
Seasonal Activity
Active year-round indoors, with reproduction and increased visibility typically peaking during warmer spring and summer months.
Description
The cellar spider is a familiar indoor companion, easily recognized by its exceptionally long legs and fragile appearance. While often overlooked or dismissed as a nuisance due to its messy webs, it serves as a beneficial household predator that helps keep populations of flies, mosquitoes, and other pests in check.
Key Features
Extremely long and delicate legs relative to a small body, elongated pale abdomen, and the distinct habit of vibrating rapidly in the web when approached.
Similar Species
Harvestmen (Order Opiliones), which are arachnids but not true spiders, distinguishable by a single fused body segment and lack of silk glands.
Life Cycle
Females carry eggs in a loose silken packet held in their jaws until hatching. Spiderlings undergo several molts before reaching maturity, with a potential lifespan of up to three years.
Ecological Importance
Acts as an effective natural pest controller in domestic and natural environments, regulating populations of insects and other arachnids.
Conservation Status
Not evaluated by the IUCN; highly stable, widespread, and successfully adapted to human-modified environments.
Interesting Facts
Despite the urban legend that they are the most venomous spiders with mouths too small to bite humans, scientific testing has disproven both claims. They are also known to aggressively hunt and consume other spiders.
Photography Tips
Use macro lenses with a steady tripod or fast shutter speed, taking advantage of side lighting to highlight the delicate leg structures and body markings without disturbing the web.
Identified: 2026-08-28T01:13:10.694149