1. Classification & Appearance

Feature                Description

Order/Family     Araneae (True Spiders) / Pholcidae (Cellar Spiders)

Body Size          Small (Females are typically 7–10 mm body length).

Legs                   Extremely long and thin, giving them their common name. The first pair of legs can be 5 to 6 times the length of the body.

Colour               Pale yellow-brown, greyish-white, or light tan. The abdomen is elongated and cylindrical.

Distinguishing Mark   The cephalothorax (front body section) often has a darker patch, vaguely resembling a human skull (hence an alternate nickname, "Skull Spider").

2. Habitat and Web

• Habitat: A synanthropic species (thrives near humans) that prefers the stable temperature and humidity of indoors. They are found globally, having spread with human travel.

  • Indoors: Cellars, basements, closets, corners of rooms, attics, garages, and sheds. They like dark, quiet, protected areas.

• Web: They construct loose, irregular, messy, three-dimensional tangle-webs in sheltered corners. They typically hang upside down in their web.

3. Diet and Hunting

• Diet: They are generalist predators, feeding on small insects like mosquitoes, flies, and gnats, as well as woodlice and other small arthropods.

• Arachnid Predators: Cellar spiders are renowned for being excellent hunters of other spiders, often invading other species' webs (including larger house spiders and even medically significant spiders like the Redback or Black Widow in other regions) to eat the host, its prey, or its eggs.

• Hunting Technique: When prey is caught in their web, they rapidly trap it with copious amounts of silk using their long legs, keeping their distance before delivering a venomous bite.

4. Life Cycle and Reproduction

• Mating: The male performs a courtship ritual, often involving vibrating and tapping the female's web and legs. Mating is direct.

• Egg Sac: The female lays 20 to 60 eggs in a cluster and wraps them in a thin, flimsy layer of silk.

• Parental Care: The female does not anchor the sac to the web; she carries the egg sac everywhere in her chelicerae (mouthparts/jaws) until the spiderlings hatch. She may continue to carry the young for a short period after they emerge.

• Lifespan: They typically take about one year to mature and can live for two or more years as adults due to the stable environment of human dwellings.

5. Behavior and Myths

• Vibrating Defense: When disturbed (poked or threatened), the Cellar Spider will rapidly vibrate and gyrate its body and web, making it a blur that is difficult for a predator to locate or catch. This gives them the nickname "Vibrating Spiders."

• Venom and Danger: The famous urban myth is that the Cellar Spider has the most potent venom but fangs too short to bite humans. This is false.

  • Venom: They are venomous (most spiders are), but their venom is not considered medically significant to humans.

  • Bite: They can bite, but documented bites are rare and only result in a mild, short-lived sting with no serious effects.