You never know what might happen if you do.

Like when Brent Askwith sprayed a spider with spider killing spray until it was really, really dead.

And caused a parasitic nematode to hastily evacuate its host:

From The Huffington Post:

That “alien worm” is actually a parasitic nematode, also known as a roundworm. While the nematode in the YouTube video is larger than most, Harvard University entomologist Dr. Brian Farrell told The Huffington Post that every human is infested with thousands of tiny nematodes. “Most have no obvious effect on us, and we are mostly unaware of their presence,” he wrote in an e-mail, “but a few are large enough to cause diseases such as trichinosis.”

I think it’s really cool, but that’s because I love parasites and intestinal worms and stuff. You?

No, you’re going to have nightmares about this. What has been seen cannot be unseen.

So next time you find a rain spider in your house, don’t kill it to death, because then the scary worm will come after you.

Remember, you would be sleeping soundly tonight if Brent had simply released the spider into his garden. (Or if you hadn’t read this post).