If you’re frightened of spiders, welcome to your worst nightmare.
For this Baltimore water treatment plant was at one point infested with 107million orb-weaving arachnids.
That 'conservative' estimate is equivalent to 35,176 spiders per cubic metre of space.
And boy did they get busy. The infestation was reported in 2009, where the spiders were found to have constructed webbing covering approximately 95% of the 4-acre building – that’s almost 16,099m2.
The “exceptional arachnid productivity” at the Back River Wastewater Treatment Plant was recorded by in 2010 in the American Entomologist journal.
The authors wrote: “We were unprepared for the sheer scale of the spider population and the extraordinary masses of both three-dimensional and sheet-like webbing that blanketed much of the facility’s cavernous interior.
“Far greater in magnitude than any previously recorded aggregation of orb-weavers, the visual impact of the spectacle was nothing less than astonishing. In places where the plant workers had swept aside the webbing to access equipment, the silk lay piled on the floor in rope-like clumps as thick as a fire hose.”
Some of the webbing was so thick it had managed to pull 8-foot long fluorescent light fixtures out of place.
More than 31,000 species were extracted from web samples, with the majority made up of Tetragnatha guatemalensis and Larinioides sclopetarius.
The report noted the spiders were not dangerous and said the webs should be removed with basic maintenance.
Though four years old, these remarkable pictures resurfaced thanks to a Halloween feature by Wired, which points out: “All recorded US megawebs have occurred near water. That makes sense because spiders have to eat, and midges emerge in huge quantities from water where they breed and live.”