I've seen too many spider bites when I was a jailer and even on my current job so if a spider is in my house, I can't just let it run free. Usually, I'll catch it in a bottle cap or something and let it go free to tell all of the other spiders of my act of kindness. It seems to be working because I've walked through spider webs before and I've never been bitten by one.
I used to enjoy compromising an insect (damage its wing or something) and tossing them into a spider web and watching the spider do its thing. Good fun. Of course, there was that one time this past summer where I caught a spider, opened my door to let the spider out, and a fucking bee flew into my house. It was all part of their plan, I imagine. I suspect the bee put the spider up to it. I killed the bee (much worse than a spider, in my opinion) and let the spider go.
Bee didn't even offer me any honey in exchange for his life. Selfish ass bee.