Believe it or not, spiders are friends, way more often than they are foes. Even if they really wanted to cause you pain, very few of the 40,000 known spider species are capable of harming humans. Spiders want nothing to do with humans that is why spider bites are extremely rare. Yes, there are dangerous spiders like the black widow, so it is best to learn to identify them to be safe.
Every house is home to spiders, the most common are cobweb spiders and cellar spiders (daddy longlegs), they are typical members of the indoor ecosystem and can do our living spaces a lot of good. In general, they like to stay out of our way, hiding out in dark places awaiting prey.
They capture and eat nuisance pests, like roaches and earwigs, and even disease-carrying insects, like mosquitoes and flies. Sometimes, they duel it out and end up killing other spiders, too. For example, our good pal the cellar spider is known to kill venomous black widows.
You’re not doing any good by killing the spiders you find in your home (unless, by some off chance, it’s one of the few dangerous varieties), and you may actually be making your home more appealing to more dubious pests by doing so. If you simply can’t stand seeing a spider inside, try to trap it and gently release it outside.
But just know that spiders are there whether you like it or not, and whether you see them or not a fact that should comfort you, not creep you out.