Cellar Spider, Daddy Long-Legs Spider, Skull Spider
Pholcus phalangioides
Pholcidae (Cellar Spiders), Order Araneae
Physical Description
Small, oval-to-round abdomen with long, extremely thin and delicate legs. The cephalothorax is pale and features a distinctive dark marking that sometimes resembles a skull shape. Overall appearance is frail and gangly.
Size Estimate
Body length is typically 7-10 mm for females, with a leg span reaching up to 5-7 cm.
Coloration & Markings
Pale gray, tan, or light brown body with faint darker markings. The cephalothorax often has a darker central pattern.
Web Type
Irregular, tangled, and formless web built in corners, ceilings, and dark recesses. They do not use sticky silk; instead, their webs act as a structural maze to tangle prey.
Eye Arrangement
Eight eyes arranged in a unique triad group on either side with two smaller eyes in the middle (though sometimes appearing as six or clustered tightly together on an elevated hump).
Leg Characteristics
Extremely long, thread-like, and fragile legs lacking heavy spination. They vibrate rapidly when disturbed as a defensive display.
Venom & Safety Information
Venom Information
Neurotoxic venom tailored for small arthropods and insects; highly ineffective against human skin.
Medical Significance
Harmless to humans. Despite urban legends regarding extreme toxicity, their chelicerae are rarely able to puncture human skin, and the venom has negligible effect.
Safety Recommendations
No safety measures needed as they are completely harmless. If relocation is desired, gently capture with a cup and paper sheet.
Habitat & Behavior
Habitat & Range
Cosmopolitan distribution worldwide. Prefers dark, humid environments such as cellars, basements, caves, and upper corners of indoor rooms.
Behavior & Temperament
Docile and non-aggressive. When threatened, they vigorously vibrate their bodies in their webs to become a blur and evade predators.
Diet & Prey
Insects and other spiders, famously including larger spiders like venomous widows and funnel-web spiders, which they subdue by wrapping them rapidly with silk from a distance.
Seasonal Activity
Active year-round indoors where climate-controlled environments provide stable temperatures and continuous food supplies.
Description
The cellar spider is a familiar indoor companion, often overlooked in the upper corners of rooms. Known universally as daddy long-legs, this harmless arachnid is a master pest controller, quietly eliminating nuisance insects and even other potentially harmful spiders from your home.
Key Features
Extremely long, fragile legs, pale translucent body, habit of vibrating when disturbed, and irregular corner web construction.
Similar Species
Harvestmen (Order Opiliones), which are not true spiders and lack a segmented waist and silk glands; Pholcus opilionoides and other Pholcidae species.
Life Cycle
Females carry eggs in a loose silk cluster held in their chelicerae until hatching. Spiderlings undergo several molts and reach maturity within a year.
Ecological Importance
Acts as a natural pest control agent inside homes and buildings by keeping populations of flies, mosquitoes, and other spiders in check.
Conservation Status
Not evaluated by the IUCN, highly secure due to successful synanthropic adaptation alongside humans.
Interesting Facts
Cellar spiders are known for hunting and consuming other spiders, including black widows, and can wrap larger prey without ever getting dangerously close.
Photography Tips
Use macro lenses with good side-lighting to capture the translucent leg joints and cephalothorax patterns. Avoid disturbing the web before shooting to prevent the blur-vibration response.
User Notes
In the corner of the living room
Identified: 2026-08-23T06:42:41.904073