Hey ! I've been wondering for a while, what would happen if there was a spider on your CPU or GPU fan when you turn the PC on ? Would the spider get sliced or ejected ? And if it gets sliced, could the blood kill the part that the spider was on ?
What's more to the point, how the heck would a spider get inside the case to start with once it's all screwed together? (unless you're in the habit off leaving the case open).
I've never found any spiders in mine (dead or otherwise) when I give it an air-blower clean twice a year.
I've worked on machines for 20 years. I've seen a few pc's that were infested with bugs(mostly roaches). I haven't seen evidence of any bugs getting sliced up in the fans(at least no blood or guts on the fan).
I guess the spider would react instantly and try its best to get away. Though, if it may get hit by the fans, I don't think they will leave any trace of blood or some sort. But let me ask you this questions, How big is the spider? And why not try to turn of your pc and try to remove it using a paper or any tool? This may answer your question. If not, thank you for reading