A New Zealand family was shocked Sunday to find that the shimmering waves that had begun to cover their local soccer field were in fact one giant spider web.

According to the Otago Daily Times, the 66-foot web is located in Papamoa, about 140 southeast of Auckland, New Zealand.

“We thought surely there are no spiders inside that,” Tracey Maris, who discovered the web with her daughter, told the Daily Times. “We walked further up, and our feet started getting stuck in the cobwebs and then we noticed little black things on top.

“So, as you do, we screamed really loudly,” Maris added. “Oh my God, they were everywhere; literally thousands of them.”

According to a local spider expert quoted by the NZ Herald, the tiny arachnids normally live in the grass, but recent flooding in the area had caused them to create the giant web for higher ground. The activity, called “ballooning” or “spider bum parachuting,” sees the spiders point their spinners in the air and shoot their silk upwards, where it is caught by the wind, which lifts and carried the spider. When thousands of spiders do this at once, it creates one giant web.

Delicate, and surprisingly pretty, the web had all but disappeared by Monday, but the spiders are still there in the grass, so who knows when it might happen again.