If you suffer from arachnophobia, stop reading now. A research team has discovered what may be the world's largest spiderweb—one that covers a staggering 1,140 square feet and hosts an estimated 111,000 spiders. It's situated inside Sulfur Cave, a lightless cavern on the Albania-Greece border. "The natural world still holds countless surprises for us," lead author Istvan Urak tells Live Science, but the surprises in this case weren't limited to the spider count. The other shock relates to the spiders themselves.
The web hosts two species that appear to amicably cohabitate: the barn funnel weaver (Tegenaria domestica) and a species of sheet weaver (Prinerigone vagans). This find, detailed in the journal Subterranean Biology, marks the first time scientists have documented colonial behavior in these species. It's an unusual arrangement, since P. vagans would typically serve as the barn funnel weaver's prey. Researchers believe the perpetual darkness may impair their vision and alter their behavior.
Instead of hunting each other, the spiders feed on nonbiting midges, which themselves rely on microbial biofilms produced by sulfur-oxidizing bacteria. The sprawling web is actually a patchwork of thousands of individual, funnel-shaped webs woven together along a narrow passage deep within the cave. To that end, the study notes "the methodology used to estimate spider density may lead to an overestimation due to the presence of abandoned funnel webs that are difficult to distinguish from those in use." The colony was first spotted by cavers in 2022.