It looked like frost—white, sparkly stuff that emerged on the ground in North Memphis, Tennessee. But the city hasn’t been treated with a beautiful freeze: Rather, reports Rachel Feltman for The Washington Post, it’s in the midst of a spider infestation that has created spiderwebs up to half a mile long.

When a gigantic spiderweb was spotted in the area, residents became “desperate for the town to take action” amidst sightings of “millions” of spiders, Feltman reports.

How could a spiderweb reach such a length?

It’s all a matter of a phenomenon called “ballooning,” writes Feltman. Spiders don’t just use their silk to spin webs: They use them to travel, too, and that’s the likely reason for this week’s massive web.

At first glance this may just look like frost on the ground, but it's actually millions of spiders showing out in one Mid-South neighborhood. >>http://shout.lt/bj6ks Posted by WMC Action News 5 on Monday, November 23, 2015

Ballooning usually occurs with baby spiders or small varieties. It takes place when spiders climb to a high point, then release a thread of silk into the air. The wind catches the silk, catching the spider in the air and “ballooning” it to another location. Warm weather this fall may have caused spider populations to spike, and that air currents could well have helped millions of babies to land in the same place, writes Feltman.

Consider it a free form of spider transportation—one that can cause whole storms of spiders. Earlier this year, a downpour of millions of small spiders encased part of Australia in webs. “This is going on all around us all the time, arachnologist Rick Vetter tells LiveScience’s Elizabeth Palermo. “We just don't notice it.” But when large numbers of spiders take off at once, it becomes quite noticeable, alarming humans.

Since the gossamer formations spotted in Tennessee are likely composed of individual strands from millions of small spiders, they might not be actual spider webs after all. But no matter what you call them, there’s nothing like the realization that millions of tiny spiders live in your midst.