Mysterious "Blanket of Webs" Covers Alberta Farm

A farmer in southern Alberta witnessed an extraordinary sight: a shimmering, silver blanket of spiderwebs covering the ground, grass, plowed fields, and pasture—as far as the eye could see. This rare phenomenon, known as mass ballooning or a communal web event, occurs when thousands of spiders disperse simultaneously.

What Causes It?

Certain cobweb spiders (family Theridiidae) build massive communal webs, often near water bodies that support aquatic insects like mosquitoes and midges. The spiders feed on these abundant insects. When conditions are right—warm temperatures, high humidity, light winds—spiderlings release silk threads to catch the wind and balloon to new locations, creating vast interconnected webs.

Is It Harmful?

No. The spiders are harmless to humans, pets, and livestock. The webs will degrade naturally within days. It's a spectacular natural event, not an infestation.

If you want confirmation, photograph the webs and spiders and contact a local university biology department or extension office.