1. Spiders don’t harm humans
All spiders are predators. To put it another way, no spider is parasitic, and so spiders rely on a diet of animal they can kill and eat. Humans aren’t on that list. While almost all spiders are venomous, many can’t pierce human skin, to begin with, and their venom isn’t potent enough to be a concern for people who aren’t allergic.
But here’s the thing; even in the case of potentially-dangerous spiders, such as the black widow or brown recluse, spiders have absolutely no reason to bite humans, except in self-defense. Spiders will very rarely get into your bed, because there’s very little for them to do there, and they can’t bite you if you roll over them, on account of the fact that they’re being crushed, and they can’t bite upward. So unless you’re actively and vigorously trying to kill a spider, the chances it'll bite you are about zero.
2. Spiders don’t muck around our food
While many insects, such as flies and ants, would like nothing more than free access to our food, spiders couldn’t care less about our bread and sugar. Your flowering plants, too, don’t interest them as a food source. Again, this goes back to spiders’ natural diet: other critters. So, if you’re worried about your food getting infested, spiders shouldn’t be your main concern, in fact…
3. Spiders are terrific pest-control
What cats are to mice, spiders are to nearly every other pest in your house. Spiders are highly skillful hunters that feed on many insects you want to keep out of your house, including flies, ants, moths, cockroaches and potentially disease-carrying mosquitoes. Having a spider in your house means pest populations will be in check.
4. Fear of spiders is literally irrational
No phobias are rational in a strict sense, but many are believed to have evolved in us to keep us safe. Cockroaches may not be an immediate threat to humans, but the diseases they carry can place us at risk. Claustrophobia, the fear of cramped spaces, stems from our tendency to always be on the lookout for means of escape. Meanwhile, arachnophobia doesn’t appear to serve any such evolutionary purpose.
Rather, it seems that we fear spiders because they just appear wrong to us. As mentioned, they have too many eyes and legs, oversized fangs, and their movements are too abrupt, triggering a defense mechanism in us, even when spiders don’t bear any ill will towards us.
Now, all of this is not to say that you should grow spiders as pets (unless you really, really want to), but that you shouldn’t freak out about them being around, and maybe consider just letting them be.