Cellar Spider, Daddy Long-Legs Spider, Skull Spider
Pholcus phalangioides
Family Pholcidae (Cellar Spiders), Order Araneae. Key family characteristics include long, delicate legs and an oval or elongated abdomen.
Physical Description
Delicate body shape with a small, fused cephalothorax and a distinctly elongated, cylindrical abdomen. The spider has very long, thin legs relative to its small body size.
Size Estimate
Body length ranges from 7 to 10 mm, with a leg span stretching up to 5 to 7 cm. This specimen appears to be an adult.
Coloration & Markings
Pale grayish-brown, tan, or yellowish overall, with faint darker markings on the cephalothorax that sometimes resemble a skull shape.
Web Type
Irregular, tangled space webs constructed in corners, cellars, and dark crevices. The web is not sticky; instead, it uses a tangled mesh to trap insects.
Eye Arrangement
Eight eyes grouped closely together on an elevated hump on the cephalothorax, consisting of a triad on each side and two smaller median eyes.
Leg Characteristics
Extremely long, thin, and fragile-looking legs with flexible joints. They often vibrate rapidly when disturbed to blur their outline.
Venom & Safety Information
Venom Information
Contains a mild neurotoxin primarily effective against small insect prey. Despite persistent urban legends, their venom is not dangerous to humans.
Medical Significance
Harmless to humans. Their fangs are generally too short or weak to pierce human skin, and envenomation effects are non-existent or negligible.
Safety Recommendations
No safety measures needed as they are completely harmless. If unwanted, they can be gently relocated outside using a cup and a piece of paper.
Habitat & Behavior
Habitat & Range
Cosmopolitan distribution worldwide. Highly synanthropic, commonly found indoors in dark, humid areas such as cellars, basements, crawlspaces, and corners of rooms.
Behavior & Temperament
Dull and sedentary when left alone. When threatened or disturbed, they perform a rapid vibrating or bouncing motion in their web to evade predators.
Diet & Prey
Feeds on a variety of insects and other spiders, including more aggressive species like venomous widows. They subdue prey by throwing silk over them from a safe distance.
Seasonal Activity
Active year-round indoors due to climate-controlled environments, with increased mobility and mating activity typically observed during warmer months.
Description
The cellar spider is a ubiquitous, harmless household guest known for its impossibly long legs and spindly frame. Often mistaken for harvestmen, these true spiders are skilled predators that help control household pests.
Key Features
Extremely long, thread-like legs, a small fused cephalothorax, an elongated cylindrical abdomen, and the distinct habit of vibrating when disturbed.
Similar Species
Opiliones (harvestmen or daddy long-legs, which are arachnids but not true spiders and lack a divided body) and Phalangium opilio.
Life Cycle
Females carry eggs in a loose silk cluster held in their chelicerae until hatching. Spiderlings undergo multiple molts and can live for several years.
Ecological Importance
Serves as an effective natural pest controller in homes and buildings, preying on mosquitoes, flies, and other household insects.
Conservation Status
Not evaluated by the IUCN, but populations are secure, abundant, and widespread globally.
Interesting Facts
Famous for the urban legend that they possess the most potent venom of any spider but cannot bite humans, which is entirely false. They frequently prey on and consume venomous black widow spiders.
Photography Tips
Use macro settings with bright, diffused lighting to capture the fine details of the leg joints and the cephalothorax markings without disturbing the spider.
Identified: 2026-09-15T19:33:55.084508