Take a walk in French Guiana’s tropical rainforests, and you’ll encounter giant spiderwebs longer than a school bus. Inside, thousands of tiny, quarter-inch-long spiders wait for their prey to be trapped, allowing the predators to rush to overwhelm their victims.

“In groups, they can capture prey up to 700 times [heavier] than each individual spider,” such as moths and grasshoppers, says Raphaël Jeanson, an ethologist who studies the behavior of animals in their natural environment at the Center for Integrative Biology in Toulouse, France. Anelosimus eximius is a so-called “social” spider that lives in large, cooperative colonies—an extremely rare lifestyle for spiders.

Not to worry, arachnophobes. Each amber-colored South American spider is