Pholcus phalangioides, commonly known as the cellar spider or daddy long-legs, is a species of spider belonging to the family Pholcidae. Native to subtropical regions but now cosmopolitan, this spider is commonly found in dark, damp places such as basements, cellars, and caves, as well as in human dwellings. It is easily recognizable by its very long, slender legs, which can be up to 50 mm long, while its body length is relatively small, measuring around 6-10 mm.

The spider’s body is typically pale, translucent beige or light brown, with a cylindrical abdomen that is sometimes slightly patterned. Pholcus phalangioides spins irregular, tangled webs in corners or under ceilings, where it hangs upside down and waits for prey. This species is an opportunistic predator, feeding primarily on small insects such as mosquitoes, flies, and other spiders, sometimes even larger spiders.

A notable behavior of Pholcus phalangioides is its ability to vibrate rapidly in its web when disturbed, creating a blur to confuse predators. Although this species has fangs and venom, its bite is harmless to humans, as the venom is weak and the fangs are too small to penetrate human skin. It plays a beneficial role in homes by controlling pest populations.