A massive spider web estimated to span about 1,000 feet blanketed a lagoon overnight in the city of Aitoliko in western Greece.

The spider web’s industrious creators, known as “stretch spiders” for their long and slender bodies, are of the genus Tetragnatha. Their impressive — and mildly terrifying — architectural ambitions have been seen in both the U.S. and Europe. The behavior is uncommon but not unheard of.

While they may be horrifying, these “long-jawed orb weavers” are completely harmless to humans. They were presumably attracted by an increasing mosquito population in the area, the presence of water, and plenty of heat. This haunting overnight soiree was the perfect place for the spider orgy.

According to Molecular Biologist Maria Chatzaki, “when an animal finds abundant food, high temperatures and sufficient humidity, it has the ideal conditions to be able to make large populations.” Luckily, she said, they won’t be around for long. “The spiders will have their party and will soon die,” she concluded.