Families living in North Memphis, Tennessee were shocked to see a half-mile long spider web on the grass. A bit late for Halloween, the spiders started creeping into doors and windows of nearby houses, sending residents into panic mode.

One of the residents commented that she saw 20 spiders on her porch. Just like many other concerned residents, she's calling for the quick cleanup of the area as there are kids running around who can get bitten by the spiders.

Professor Susan Riechart from the University of Tennessee said that discomfort over the unexpected throng of spiders is reasonable but there is no need to be scared. The phenomenon is called a ballooning event. This is when small, young spiders 'float off' and set forth into their journey into the world. Ballooning events are quite common and the season's warm weather may have prompted the phenomenon. Certain air currents are good for ballooning events. Most spider families send out the younger generation into the world by dispersing silk threads over a meter long.

"This would explain the fact that thousands to hundreds of thousands may take off at the same time," explained Riechart, who is also the American Arachnological Society's former president.

When the tiny spiders get caught by the air currents, they can't control where they will land. This explains why many spiderlings end up in the same area. Riechart added that the spiderlings' mouth parts are not large enough to pierce human skin, making them totally harmless.

"You get this all the time. But it's really quite cool to see them all in one area," said Lachlan Manning, Australian Museum's live exhibits officer. Manning added that the Tennessee trail is an accumulation of small spider webs and not simply a giant one.

The ballooning phenomenon in Memphis is actually a sign that, ecologically speaking, all systems are working just fine. When spring comes, the local spiders will feed on mosquitoes and crop-eating insects. Until then, perhaps, the local residents will be glad for their friendly, neighborhood spiders who are flying and crawling into porches lately as they make their way into the world.

Photo: Scott Anderson | Flickr