Scientists have discovered what may be the largest spider web in the world inside a cave stretching across Greece and Albania.
The web, covering 106 square metres, is home to about 100,000 spiders from two different species—something never seen before.
The cave, known for its strong smell like rotten eggs, was first explored in 2022 by adventurers who told scientists about the strange find. Inside, researchers found about 69,000 barn funnel weaver spiders and 42,000 sheet weaver spiders all living together in a massive web.
This discovery surprised experts because spiders usually prefer to live alone, especially the barn funnel weaver, which is known to eat other smaller spiders like the sheet weaver. Yet in this dark cave, the two species worked together peacefully.
The cave’s strange environment might explain why. It has no light but plenty of food, thanks to tiny midges flying around. These midges feed on crustaceans, which in turn eat microbes living in the cave. The spiders then eat the midges, giving both spider species enough to survive without needing to fight.
The cave formed from sulphuric acid reacting with gases underground, creating a unique place for animals to live. DNA tests also showed that the cave spiders are different from their relatives outside, meaning they may have changed to suit their unusual home.
I have always wanted to travel all around Europe