Cellar Spider, Daddy Long-Legs Spider, Skull Spider
Pholcus phalangioides
Pholcidae (Cellar Spiders), Order Araneae
Physical Description
Small, oval-shaped body with very long, delicate, thread-like legs. The cephalothorax is short and wide, and the abdomen is typically elongated or cylindrical. They have a fragile, translucent appearance with smooth skin.
Size Estimate
Body length is about 7-10 mm, with a leg span reaching up to 5-7 cm. This appears to be an adult specimen based on proportions.
Coloration & Markings
Pale grayish-yellow to light brown, sometimes featuring darker markings on the cephalothorax that resemble a skull shape, which gives them one of their common names.
Web Type
Irregular, sticky tangle webs (cobwebs) constructed in dark, damp corners, high up near ceilings, or in cellars and basements.
Eye Arrangement
Eight eyes arranged in two lateral triads and a pair of smaller median eyes situated on a raised tubercle.
Leg Characteristics
Extremely long, thin, and flexible legs with no distinct spines. They vibrate rapidly when disturbed as a defensive mechanism.
Venom & Safety Information
Venom Information
Contains a weak neurotoxin that is completely ineffective against humans due to their small fangs and low venom volume.
Medical Significance
Harmless. They are not medically significant, and their fangs are generally too small to pierce human skin.
Safety Recommendations
No safety measures needed as they are completely harmless. If they are in unwanted locations, they can be gently relocated using a cup and a piece of paper.
Habitat & Behavior
Habitat & Range
Cosmopolitan distribution worldwide. Frequently found inside human dwellings, particularly in dark corners, basements, attics, garages, and around ceilings.
Behavior & Temperament
Docile and completely harmless to humans. When disturbed, they perform a rapid spinning or vibrating motion in their web to blur their image and confuse predators.
Diet & Prey
Insects and other spiders, famously including larger spiders like venomous widows and hobo spiders, which they successfully hunt and consume.
Seasonal Activity
Active year-round indoors, as they benefit from constant indoor temperatures and shelter from winter conditions.
Description
The cellar spider is a familiar household guest across the globe. Recognizable by its remarkably long, spindly legs and delicate body, this master of the upper room corners is a silent and efficient protector against unwanted insect pests.
Key Features
Extremely long legs relative to body size, pale coloration, habit of vibrating when disturbed, and presence of irregular indoor cobwebs.
Similar Species
Opiliones (Harvestmen, also called daddy long-legs, which are not true spiders) and crane flies, both of which lack silk-producing spinnerets and have fused body segments.
Life Cycle
Females carry eggs in a loose silk cluster held in their chelicerae until they hatch. Spiderlings undergo several molts to reach maturity, living for up to several years.
Ecological Importance
Acts as an effective natural pest control agent inside homes, reducing populations of mosquitoes, flies, and other potentially problematic insects.
Conservation Status
Not evaluated by the IUCN, highly secure and thriving globally due to close association with human habitats.
Interesting Facts
Despite an urban legend claiming they are the most venomous spiders with mouths too small to bite, this is entirely false; their venom is actually quite weak.
Photography Tips
Use a macro lens with good side lighting to highlight the delicate leg structure and translucent body details against a neutral background.
Identified: 2026-09-14T22:48:48.778043