Spiders are good for you. They are almost as venerable as the almighty camel. I'm keen on keeping them in my place. If it's getting too much, I take away some of their webs or if they overpopulate, I take a few of them out of the house but generally I let them go about their business.

I'm not much of an insect killer anyway, I even let the common house flies escape. Except gnats. For them it's sudden death.