--- title: "Long-Bodied Cellar Spider (Pholcus phalangioides) | AnimalTracks.wiki" description: "The ceiling spider that raids other spiders' webs and spins itself into a blur when threatened." image: "https://animaltracks.wiki/images/animals/long-bodied-cellar-spider-1.webp" published: "2026-10-11" updated: "2026-10-11" --- # Long-Bodied Cellar Spider (*Pholcus phalangioides*) > **Status**: Checked against 7 sources, listed under Sources below. > **Tagline**: The ceiling spider that raids other spiders' webs and spins itself into a blur when threatened. > **Soundtrack Vibe**: Dream Pop & Shoegaze // My Bloody Valentine, "Soon" > **Soundtrack Links**: [Spotify](https://open.spotify.com/track/4TJVYq699BO7PagAjXxYhJ) > **Vibe Match**: Guitars bent into a spinning wash, for a spider that, when its web is disturbed, swings its body around fast enough to become very hard to see. ## Biological Superpowers & Stats - **Taxonomy**: *Pholcus phalangioides* - **Danger Level**: Low - **Conservation Status**: Not Evaluated ([IUCN Red List](https://www.iucnredlist.org/)) - **Superpower**: Spins its body into a blur when its web is disturbed, and walks into other spiders' webs to eat them - **Habitat**: Worldwide, in dark, undisturbed places such as basements, caves and the corners of homes - **Diet**: Apparently prefers other spiders and small insects - **Tags**: arachnid, predator, urban ## Natural History & Behavior ## A Spider That Hunts Spiders The long-bodied cellar spider, *Pholcus phalangioides*, builds a web to catch prey, but it also invades the webs of other spiders. Females have been seen invading a neighbour's web, eating the owner, and then using that web to catch new prey. A study of its hunting found it acts as an aggressive mimic, making special vibrations that the web's owner responds to as it normally would to its own prey. On its own web, it is most efficient at catching spiders and, especially, insects. When prey trips a line at the edge of the web without entering it, it leans out and throws silk over the victim, keeping as few as two legs on the web. It attacks prey by wrapping it in silk. ## Tiny Body, Giant Legs Females are 7 to 8 millimetres long and males are 6 millimetres. The forelegs of an adult female are about 50 millimetres in length. The abdomen is about three times as long as it is wide, and the body is pale yellow-brown with a large gray patch in the center of the cephalothorax, the front body section. The body and legs are almost translucent, and under a microscope you can see blood cells moving in the legs and body of a living spider. Penn State Extension says it takes about a year for the spiders to mature, and they can live for two or more years as adults. A female carries her eggs, wrapped in silk in clusters of 25 to 60, in her jaws as she hangs upside down in her web. ## Now You See It, Now You Don't > **Whirling** The spider swings its body around in a circle while keeping its long legs on the silk, and a lab experiment gave further evidence that this is an effective defence against jumping spiders. When its web is disturbed, it swings fast enough to become very hard to see. *Portia*, a genus of jumping spiders, preys on it in nature, and birds are listed as known predators. ## Found Almost Everywhere This spider lives throughout the world, and it is common across the United States. ITIS lists it as introduced in both Canada and the continental US. It can be found in undisturbed, low light spots such as basements, caves, and under stones and ledges. Many people know it from the ceilings and corners of homes, where it builds large, loose, flat webs. Penn State Extension calls it the most common of its family in the United States, adds that it is not known to bite people, and says it is not medically important. ## Frequently Asked Questions ### Is the daddy long-legs the most venomous spider in the world? No. The story says the venom of cellar spiders is the most potent of any spider for mammals, and would be lethal if only their fangs could pierce human skin. A 2019 study of a different cellar spider, Physocyclus mexicanus, says reports of high potency come from rumor and non-scientific anecdote. The fangs of adult males of that species can pierce uncalloused human skin, and documented bites typically cause a mild sting with no long-lasting effects. From that species, the authors conclude that the effects of cellar spider bites on humans and other mammals are inconsequential. *(Source: [Zobel-Thropp et al. 2019]())* ### Is a harvestman the same animal as a daddy long-legs spider? No. Daddy long-legs is a common name shared by the cellar spider and by harvestmen, which Animal Diversity Web says are not true spiders. People often mix the two up. *(Source: [Animal Diversity Web, University of Michigan]())* ### Why does the cellar spider spin in its web? The spinning is called whirling. A laboratory study found that this spider whirled for several hours a day in the presence of jumping spiders, and hardly ever with predatory spiders from eight other families. The authors suggest the long spin may disturb a jumping spider's ability to keep its eyes fixed on its target. *(Source: [Heuts et al. 2001]())* ## Sources 1. [Pholcus phalangioides. Animal Diversity Web, University of Michigan.]() 2. [Longbodied Cellar Spider. Penn State Extension.]() 3. [Jackson & Brassington (1987). The biology of Pholcus phalangioides (Araneae, Pholcidae): predatory versatility, araneophagy and aggressive mimicry. Journal of Zoology.]() 4. [Jackson (1990). Predator-prey interactions between jumping spiders (Araneae, Salticidae) and Phokus phalangioides (Araneae, Pholcidae). Journal of Zoology.]() 5. [Heuts et al. (2001). Long-duration whirling of Pholcus phalangioides (Araneae, Pholcidae) is specifically elicited by Salticid spiders. Behavioural Processes.]() 6. [Zobel-Thropp et al. (2019). Not so Dangerous After All? Venom Composition and Potency of the Pholcid (Daddy Long-Leg) Spider Physocyclus mexicanus. Frontiers in Ecology and Evolution.]() 7. [Pholcus phalangioides (Fuesslin, 1775), Taxonomic Serial No. 865102. Integrated Taxonomic Information System.]() *Published October 11, 2026. 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