My stepdad used to tell me about "spider karma" when I was little. Basically, all spiders are a part of a gang, and if you squash one they'll just think he must've stepped out of line or something. However if you squash 3 or more, the spiders will all start talking to each other and plan out attacks on you when you're most vulnerable. Sleep attacks are the most common, but occasionally they'll get so pissed they choose to hide in a jacket or shoe and sacrifice everything just to inflict a little pain and terror for killing their mums or siblings.
I used to actually believe this btw.
Edit: why the downvotes to OP? home maintenance is always the best method for keeping pests out. No need for spiders indoors if ya dont have bugs indoors!