Put down the bug spray: That spider is not coming to get you, it doesn't want to bite you, and it probably couldn't hurt you even if it did.
Like bats, spiders devour harmful insects and mostly stay out of humans' way. Yet many people fear them, squish them, or scream and shudder at the sight of them. Spiders are not bloodsuckers, and they have no reason to bite anything that's too big for them to eat [source: Crawford].
In fact, arachnologist Rod Crawford of the Burke Museum of Natural History and Culture writes that he has been bitten only twice over a 30-year career of handling tens of thousands of live ones. In the rare instance that spider bites do occur, it's probably because someone startled the arachnid by reaching into a space it was occupying. Even the so-called aggressive house spider, also known as a hobo spider, isn't particularly aggressive toward humans. It may bite if it fears that its egg sac is in danger but would rather avoid you than seek you out [source: Orkin].
Think you have a spider bite? Unless you actually saw the spider bite you, it's much more likely to be a flea or bedbug bite, a viral or bacterial infection, reaction to poison ivy, or even skin cancer [sources: Main, Palermo].