Cellar Spider, Daddy Long-Legs
Pholcidae (likely Pholcus phalangioides)
Pholcidae (Cellar Spiders), Order Araneae. Key family characteristics include extremely long, delicate legs and oval to cylindrical abdomens.
Physical Description
The spider has an extremely delicate and fragile appearance with a small, rounded cephalothorax and an elongated, cylindrical abdomen. The proportions are dominated by exceptionally long, thread-like legs.
Size Estimate
Body length is typically around 7 to 10 millimeters, with a leg span reaching up to 50 millimeters or more, placing it in the typical adult size range for common cellar spiders.
Coloration & Markings
Pale, translucent gray, tan, or yellowish coloration. The cephalothorax often features a darker median marking, and the abdomen may have subtle grayish or brownish spots or chevron patterns.
Web Type
Irregular, three-dimensional tangle webs or sheet webs built in dark, sheltered corners, often close to the ground, under furniture, or in cellars.
Eye Arrangement
Eight eyes arranged in a tight cluster on an elevated portion of the cephalothorax, consisting of a triad on each side and a pair of smaller median eyes.
Leg Characteristics
Extremely long, thin, and fragile legs with slight dark banding. They lack heavy spination and are known for vibrating rapidly when disturbed as a defensive camouflage mechanism.
Venom & Safety Information
Venom Information
Neurotoxic venom tailored specifically for small arthropods. Despite urban legends about extreme toxicity, their venom is extremely mild to humans and they rarely bite.
Medical Significance
Harmless to humans. Their mouthparts are generally too small or weak to pierce human skin, and envenomation poses no medical risk whatsoever.
Safety Recommendations
No safety measures needed as they are completely harmless; they can simply be left alone to perform natural pest control or gently relocated using a cup and paper.
Habitat & Behavior
Habitat & Range
Cosmopolitan distribution found worldwide in human dwellings, basements, cellars, garages, caves, and sheltered outdoor crevices.
Behavior & Temperament
Docile and non-aggressive. When threatened, the spider rapidly vibrates its web to become a blur, making it difficult for predators to target.
Diet & Prey
Generalist predator feeding on small insects and other spiders, famously including venomous species like widow spiders and hobo spiders, which they easily subdue using length and silk wrapping.
Seasonal Activity
Active year-round indoors, as they benefit from climate-controlled environments, though breeding activity often peaks during warmer months.
Description
Commonly known as cellar spiders or daddy long-legs, these gentle inhabitants of dark corners are master pest controllers that silently keep household insect populations in check.
Key Features
Extremely long, spindly legs paired with an elongated or oval pale body, and the distinctive habit of bouncing or vibrating rapidly in the web when disturbed.
Similar Species
Harvestmen (Order Opiliones), which are arachnids but not true spiders; harvestmen lack a segmented waist and silk glands.
Life Cycle
Females carry eggs in a loose silk sac held in their chelicerae until hatching. Spiderlings undergo multiple molts to reach maturity, with adults living for several years in optimal conditions.
Ecological Importance
Serves as an effective natural pest control agent inside homes and buildings, managing populations of flies, mosquitoes, and other household pests.
Conservation Status
Not evaluated by the IUCN, but highly secure and ubiquitous globally due to their close association with human habitations.
Interesting Facts
Cellar spiders are famous for invading the webs of other spiders, mimicking prey to lure the host out, and then consuming them.
Photography Tips
Use macro lenses with adequate lighting or a ring flash to highlight the delicate leg structures and eye arrangement against dark backgrounds.
User Notes
Under a chair
Identified: 2026-08-14T10:07:11.798574