Researchers have identified what may be the world's largest spider‑web complex in Sulphur Cave on the Greece–Albania border, covering about 106 sq m and housing over 111,000 spiders. The structure is a mosaic of funnel‑shaped subunits apparently built cooperatively by two normally solitary species: roughly 69,000 Tegenaria domestica and 42,000 Prinerigone vagans. Lead author István Urák suggests the cave's dark, sulphurous environment may have favoured this unusual cohabitation; the study was published in Subterranean Biology.
Massive Spider‑Web "Mosaic" Housing 111,000 Spiders Discovered in Sulphur Cave
Researchers have identified what may be the world's largest spider‑web complex in Sulphur Cave on the Greece–Albania border, covering about 106 sq m and housing over 111,000 spiders. The structure is a mosaic of funnel‑shaped subunits apparently built cooperatively by two normally solitary species: roughly 69,000 Tegenaria domestica and 42,000 Prinerigone vagans. Lead author István Urák suggests the cave's dark, sulphurous environment may have favoured this unusual cohabitation; the study was published in Subterranean Biology.
23:36, 07.11.2025Science
World's largest known spider‑web complex discovered in Sulphur Cave
Researchers report the discovery of what appears to be the world's largest known spider‑web complex inside the remote Sulphur Cave on the Greece–Albania border. The silk network covers roughly 106 square metres and, according to a study published last month in Subterranean Biology, shelters more than 111,000 spiders.
The extensive web runs along the passage walls and is made up of countless funnel‑shaped substructures that together form a striking "web mosaic" visible in photographs and video released by Greek media. In their paper the scientists describe the formation as an "extraordinary colonial spider assemblage."
Remarkably, the mosaic appears to have been constructed cooperatively by two different species: approximately 69,000 individuals of the common house spider Tegenaria domestica and about 42,000 of Prinerigone vagans, a species normally associated with canopy habitats. Both species are typically solitary and are most often found near human settlements, making this large‑scale cohabitation highly unusual.
Lead author István Urák (Sapientia University, Romania) suggests that the cave's extreme, dark and highly sulphurous conditions may have promoted tolerance between the species and encouraged communal living.
Photographs and video provide visual evidence of the structure's scale and complexity. The finding highlights how harsh subterranean environments can drive unexpected animal behaviours and opens new questions for research about construction coordination, resource sharing and population dynamics within such colonies.
Study: Subterranean Biology (published last month). Location: Sulphur Cave, Greece–Albania border.