If the spider is a native to the area, it will likely be able to survive outside, Crawford said. But if the spider is a transplant that’s become a house spider — even if its ancestors made the voyage to the “new” place decades to hundreds of years ago — odds are, the spider will perish outside, Crawford said.
That’s because most spiders are adapted to specific places and temperatures, Crawford said.
“The American house spider (Parasteatoda tepidariorum) [is] probably native to northern South America,” Crawford said. “It undoubtedly lives outdoors just fine if your backyard is in Brazil or Guyana.” Even species that moved from one climate to a similar one seem to have trouble. Take the giant house spider (Eratigena atrica), a native of England. It traveled west when the British settled British Columbia, Canada, and the species later made its way south, to Seattle.
Now, E. atrica can be found in houses across parts of the northwestern U.S. (including this reporter’s childhood home). But the species is hardly ever found outside, even though Seattle’s climate is fairly similar to London’s.
“You would think it could survive outside, but we never find it in natural habitats around here — just [in] man-made habitats, such as buildings, brick piles, junk piles and retaining walls,” Crawford said. "So, it does, in fact, survive to some extent outside of buildings, but always in a man-made shelter."
What to do
If you see a spider creep across your bedroom, don’t squish it — but don’t throw it outside, either, Crawford said. Instead, move it to another part of your residence where you don’t mind having spiders, such as the garage, he suggested.