These Spiders Create 50,000-Strong Armies In The Peruvian Rainforest


Tom Hale

Tom is a writer in London with a Master's degree in Journalism whose editorial work covers anything from health and the environment to technology and archaeology.

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840 These Spiders Create 50,000-Strong Armies In The Peruvian Rainforest
Bernard DUPONT/Flickr. CC BY-SA 2.0

You probably think of spiders as solitary creatures, sitting alone in their webs like a surly miser. But the arachnophobes among you won’t be pleased to learn there’s actually a species of spider that enjoys creeping around with tens of thousands of comrades.

These social spiders, Anelosimus eximius, are known to exist in armies of over 50,000 and live in webs over 7.6 meters (25 feet) long and 1.5 meters (5 feet) wide. Amid these communes, all the spiders help with the housekeeping around the web, collectively gather their trapped prey and communally eat together. There can be up to 40 of these massive webs within just a few kilometers in the South American country of Peru where they're found.


Each spider metropolis is largely dominated by females, with males thought to make up between 5 percent and 22 percent of the total population.

In a write-up for BBC Earth, Dr. Jason G. Goldman, an animal behavior expert, described his encounters with these social spiders while on his ventures into the Peruvian Amazon jungle.

“As I watched the social spiders go about their day deep in the jungle, a bee found itself stuck in the giant web.” he explained. “Suddenly, dozens of the eight-legged predators descended en masse onto the struggling black-and-yellow striped bug. It was impossible to see through the writhing mass of tiny spider legs, but one thing was certain: that bee was done for.”



There’s thought to be around 24 other spider species that exhibit this level of bee-like sociality. But unlike elitist bees and aristocratic ants, social spiders are a lot more egalitarian – with all spiders capable of breeding and performing any job.

"They're incredibly well organized," arachnologist Jonathan Pruitt of the University of California, Santa Barbara, told BBC Earth. "Spider vocations are intimately tied to their efficiency at those vocations."

He added: "In spite of a lack of genetic diversity, they exhibit this exquisite diversity in terms of their personalities."


To conclude: If you want to stay away from a hyper-organized, 50,000-strong army of spiders, stay out of the Peruvian rainforest.

Main image credit: Bernard DUPONT/Flickr. CC BY-SA 2.0


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