Spiders don't know that many humans are terrified of them, nor do they heed the traditional "less than a million babies per mom" rule humans find easy to follow.
So when spiders are left undisturbed inside a structure humans rarely visit they tend to reproduce in staggering numbers, since there aren't any humans around to shriek at them and spoil their fun.
When employees at Baltimore's Wastewater Treatment Plant began noticing the webs back in 2009 they had no idea how much real estate those arachnid clans had taken for their own.
Pest controllers discovered an estimated 95 percent of the four acre building was covered in webs, home to over a hundred million long-jawed orb weaver spiders (an estimated 35,176 spiders per square meter).
Maybe it's a shooting location for an all arachnid version of The Wire?