A half mile long spiderweb was spotted by residents in North Memphis, Tenn. on Monday morning. Local news outlets are reporting that there are millions of spiders in and around the web. The size of the web, and amount of spiders has residents concerned.

The Washington Post reports that the increase of spiders is nothing to be concerned about. The large area of webbing is due to a “ballooning” event. Ballooning is when young spiders float off of the web, going out on their own into the world.

However,some are urging that action be taken toward the spiders. “Clean this area up and spray for these spiders,” North Memphis resident Ida Morris said. “There are kids running around. A spider could bite the kids.”

Ballooning events are actually extremely common, according to Susan Riechart, a professor at the University of Tennessee Knoxville. Riechart said that she has seen a few cases in her area, and believes that the unseasonably warm fall temperatures caused the dispersal.

“Particular air currents favor ballooning,” Riechart said. “This would explain the fact that thousands to hundreds of thousands may take off at the same time.” The spiders have no control over where they land, but based on the air currents, it is not unusual for them to fall in relatively the same area. The spiders that “suddenly” appeared have likely been there for years.

The spiders in the area are thought to have mouth parts too small to bite humans, making them harmless to North Memphis residents. The large presence of spiders indicates that the ecological systems in the Memphis area are operating normally.