1. Spiders are not insects. In fact, from my experience, a lot of proper insecticides don't do squat to spiders. The toxicity pathways are simply different between insects and spiders, I guess.
2. I actually like ants, unless you're talking about the really nasty ones like army ants or red fire ants. I don't mind them in my house, stealing my food; I just don't want to accidentally kill them. Some people raise them in formicariums (like aquariums, but for ants). I used to have a formicarium when I was in Canada, but have been having trouble trying to start a Carebara affinis or Carebara diversa colony in Hong Kong. Ants, like a lot of other apocrita, are actually quite "hygiene-conscient", almost to the point of OCD. Ants are also pollinators and scavengers that clean up the ground by carrying whatever they can eat into their nests. I have never heard about ants being vectors of human-affecting diseases.
Spiders don't stand a chance against orange oil concentrate. It handily kills them right along with every other crawly thing. I won't spray the ones that stay up high, but if you've ever seen a Wolf spider in your house, you'd spray them, too. They can get rather large. If only I could convince my wife to move someplace civil like Vermont or just slightly east of Seattle, like Issaquah or Snohomish. Texas has too many critters. Where I live, the coons will attempt to gain entry into your trash cans, the possums will be under your cars and hiss at you, the snakes are ever present. Just down the street from us, a family killed two water moccasins in their back garden a couple of weeks ago. They also have seen several copperheads. Both are venomous.
I forgot to advocate for the spiders, again, except the really nasty ones. E.g. during damp seasons, I catch and deploy jumping spiders into my daughter’s room as a method of biological control against book lice.
In my opinion, if you have any kind of spider infestation on your property, then you have something else to worry about. Spiders need food to thrive, which usually means insects or other arthropods, which in turn means you have an infestation of other arthropods.
So why are you having a bug infestation in the first place? Are you leaving food crumbs all over the place? Do you have damp places where fungi and moss will grow? Insects and all kinds of critters really like those conditions. If you fix those, your insect and (consequently) spider infestation will most likely be gone.
In the case of mosquitoes, we are the food, so you can’t fix that, but you can clear out bodies of still water, which will decimate the number of mosquito larvae.
Killing them (with insecticides) only fixes the symptoms, not the root of the problem.
I have lived in or just outside of Chicago my entire life, and the worst critter I've encountered are centipedes, which I handle incredibly poorly. I honestly don't think I would manage well with encountering snakes or wolf spiders with any frequency.
I live less than 1000' from the water's edge, so mosquitoes are ever present for about 9 months of the year. I've tried citronella candles when out BBQing, watching my children play in the lawn, etc. I don't like dousing myself in chemicals, so I don't spray myself with deet, etc. They are a nuisance for which there is little to be done other than avoidance.
If you can stand the smell, neem oil is very effective. I use low concentrations in a spray bottle, and spray my windows, they generally don't come in..
Orange oil, bay leaves, and baking soda/sugar mix are all non-toxic to humans and animals, and all cheap. And they all work very well.
Where I live, the only insects I will not kill are the spiders. They hang out under my roof line and eat all the bad flying insects like mosquitoes.