Should you or shouldn't you kill spiders in your home?

Chances are, you react to seeing a spider in your home in one of two ways: You either let it be or kill it with fire. Of course, most people don't prefer creepy-crawly insects getting cozy in their living room. But is killing them the best option?

Eight-Legged Allies
Let's get one thing straight: 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, spider expert Jo-Anne Sewlal of the University of the West Indies told National Geographic. Typically, spiders want nothing to do with you. It goes without saying, then, that spider bites are extremely rare. That's not to say there are no dangerous spiders, though. Read up on venomous spiders in your region — like the black widow and the brown recluse — and learn to identify them, just to be safe.

North Carolina State University entomologist Matt Bertone conducted a survey of 50 North Carolina homes to see which arthropods are living under our roofs. Perhaps not shockingly, every house they visited was home to spiders. The most common were cobweb spiders and cellar spiders (often called daddy longlegs).

This finding shouldn't scare you — it's perfectly normal. Spiders are pretty 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. Thanks, spider bro!

Spidey Senses Tingling
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.

Okay, there is one tiny exception. Spider expert Christopher Buddle of McGill University tells National Geographic that non-regional spiders in your home are better off, well, offed. If you bring home, say, bananas from the grocery store and notice a spider in the bunch, that's one you can take out a hit on. "[A]lthough it pains me to say this [as an arachnologist], the best course of action is to probably to kill the eight-legged cargo," says Buddle. Because this spider is non-native to your region, releasing it outside could cause harm to the plant and animal life that does belong there.