
The bad news: The four-acre spiderweb discovered at one of the Baltimore Wastewater Treatment Plants was home to more than 107 million spiders (by one โmarkedly conservativeโ estimate), with as many as 35,176 spiders per square meter. (Ick ick ick ick ick.)
The good news? This all got taken care of back in 2009, so you arachnophobes can calm down.
This four-year-old spider news gained recent traction when Wired and other publications discovered a 2010 paper entitled โAn Immense Concentration of Orb-Weaving Spiders With Communal Webbing in a Man-Made Structural Habitatโ in the journal American Entomologist.
According to the article, this was by far the largest reported concentration of orb-weaver spiders. Spiderwebs were โas thick as a fire hose,โ and in places the webbing was so dense it pulled 8-foot light fixtures out of place. (Shudder.)

Apparently, these spider mega-cities tend to crop up in places near large water supplyโwhich is probably why they all moved into the wastewater treatment plant.
Thereโs no word of how the plant managed to get rid of the spiders. Probably better not to know.
