Never Kill the Spider Above Your Bed — It's Hunting Something Worse

Should you kill the spider above your bed? Put the shoe down. The thin, long-legged cellar spider in your ceiling corner, often called the daddy long-legs spider, is hunting something worse: other spiders. In a lab, it shakes another spider's web like a trapped insect, and when the owner comes out, it eats the owner. In one bedroom in England, it ate a house spider at least twice its weight. In a garden shed in Aldershot, all 102 meals taken from its webs were spiders or their relatives. Not one insect. On MythBusters, Adam Savage put his arm in a box of their close relatives, and the bite was a short, mild sting. A lab study in Brazil shows the limit: it beats the dangerous brown spider, but it takes the easy fly first. Spiders in your house? In one US study, cellar spiders lived in 84 percent of 50 homes. 0:00 A spider above your bed 0:24 The shoe in your hand 0:58 It tricks other spiders 2:41 One bedroom, one big spider 4:09 A summer of spider meals 5:56 Can it bite you? 7:32 Free pest control? 9:19 Shoe, glass, or leave it Every study behind this video is listed below. 📚 RESEARCH & SOURCES: ▸ The web trick: "The biology of Pholcus phalangioides: predatory versatility, araneophagy and aggressive mimicry" by Jackson, Brassington (1987, Journal of Zoology) : it shakes other spiders' webs like trapped prey and eats the owners; it ignores prey away from webs. ▸ The bedroom: "Does Pholcus lure its prey with pheromone mimics?" by Hopkin (2000, British Arachnological Society Newsletter 87) : one large male Tegenaria, moved away for six days, at least twice the cellar spider's weight by his estimate; n=1. ▸ The garden shed: "Araneophagy in Pholcus phalangioides" by Crooke (2002, British Arachnological Society Newsletter 93), citing Bristowe (1958) : April to September 2001; 102 prey items, 63 house spiders, 6 cellar spiders, the rest arachnid remains; all 8 female house spiders nearby survived. ▸ The bite and the venom: "Not so dangerous after all? Venom composition and potency of the pholcid spider Physocyclus mexicanus" by Zobel-Thropp et al. (2019, Frontiers in Ecology and Evolution) : MythBusters, 15 February 2004, a male P. mexicanus bit Adam Savage, a brief mild sting; in mice, black widow venom is the stronger. ▸ No toxic effect on people, as reported by UC Riverside Entomology, "Are daddy longlegs really the most venomous spiders in the world?" (2022, from Live Science) : Rick Vetter. ▸ Who lives in your house: "Arthropods of the great indoors" by Bertone et al. (2016, PeerJ) : 50 homes in one US region; cellar spiders in 84 percent; pests rarer than harmless kinds. ▸ Fear of spiders: "Measuring fear evoked by the scariest animal" by Polák et al. (2022, BMC Psychiatry) : 10.3 percent of 3,863 Czechs above the cut-off for spider phobia; 2.7 percent of Dutch adults, as reported by this paper. ▸ Against the brown spider: "Interações predatórias entre Pholcus phalangioides e Loxosceles intermedia" by Fischer, Krechemer (2007, Revista Brasileira de Zoologia) : lab, Curitiba, 2004 to 2006; killed the brown spider 77 times, killed by it about ten times; on average about five times lighter; chose insects first. ———————————————————— PEOPLE, PLACES & ANIMALS MENTIONED IN THIS VIDEO: ▸ Cellar spider (Pholcus phalangioides): the thin, long-legged spider above your bed, and the hunter of this video. ▸ House spider (Tegenaria; in the shed count Tegenaria domestica): the big spider it eats, in the bedroom and in the shed. ▸ Brown spider (Loxosceles intermedia): the dangerous spider of Curitiba, which the cellar spider beat in the lab. ▸ Physocyclus mexicanus: a relative of the cellar spider, the one that bit Adam Savage. ▸ Black widow (Latrodectus): its venom is stronger in mice. ▸ Robert Jackson and Roxanne Brassington: watched cellar spiders hunt on other spiders' webs in their lab. ▸ Steve Hopkin: spider scientist who saw a cellar spider eat a house spider in his own bedroom in England, 1999. ▸ Raymond Crooke: counted every meal in the cellar spider webs of his garden shed in Aldershot, England, in 2001. ▸ Bristowe: wrote in 1958 that cellar spiders eat other spiders, the hunch behind Crooke's count. ▸ Adam Savage: put his arm in a box of spiders on MythBusters, 2004. ▸ Rick Vetter: spider expert at UC Riverside; knows of no toxic effect of cellar spider venom on people. ▸ Matthew Bertone: led the count of small animals in 50 US homes. ▸ Polák: led the survey of fear of spiders among 3,863 Czechs. ▸ Marta Fischer and Flávia Krechemer: set cellar spiders against brown spiders in Curitiba, Brazil. ———————————————————— 🎨 Animation by Fulcrum ———————————————————— #spiders #cellarspider #arachnophobia