In a bizarre spectacle that left villagers scratching their heads, a colossal "spider web" mysteriously appeared overnight on a hillside behind a house in southern China.

The video was filmed in Dehua County in Fujian Province on April 15.
The web, which covered an impressive area of over 30 square metres, was not spun by spiders but was instead densely packed with caterpillars, each sporting thick, fluffy hair.

Mr. Lin, a local resident, discovered the phenomenon and described it as both fascinating and slightly terrifying, remarking that the sheer size of the web made it seem as though the spiders had become spirits. "It's so big; it feels like the spiders are almost magical, a bit scary," Lin said.

Upon examination of the video footage, an official from the Dehua County Forestry Bureau identified the culprits on April 16 as "tent caterpillars," known for their habit of clustering together and spinning massive webs.

The official sought to reassure the public, explaining that while the sight was unusual and the caterpillars do pose a threat to trees by eating the leaves, particularly of fruit trees, they do not cause significant harm to the broader ecosystem.

"There’s nothing too alarming," the official stated. "These tent caterpillars hatch in April and naturally spin together in large groups to form such webs, though it’s rare to see one this large. Once they pupate and turn into moths, they’ll just fly away."

The video was provided by local media with permission.

4月15日，福建泉州德化县， 村民林先生发现，房屋后面的山坡上，一夜之间出现巨幅“蛛网”。
林先生称，整个面积看起来有三十几平方，这蜘蛛网上全部都是毛毛虫，很大的毛，很多很多一片。这么大的网，感觉像是蜘蛛成精了，有些恐怖。
4月16日，德化县林业局一名工作人员表示，根据视频，初步判断是“天幕毛毛虫”。
该工作人员说:“没有什么大惊小怪的。这个天幕毛毛虫一般是4月份孵化出来，按它们的习性，会成群结队，然后吐丝结成大网，只是结这么大网还是少见。对正常树木肯定会有危害，比如会吃果树树叶，但不会对整个生态系统造成影响。后面结蛹变成蛾的时候就飞走了。”