I’ve had fruit flies before that must have come in on some produce, have to be on it to clear them, leave out any fruit/veg scraps and they come out (out being tossed in the trash/green bin too, anything open air). Drop of dish soap, water and vinegar in a high walled glass or jar is the way to do it, I used balsamic but malt or wine vinegar works too, just leave that out and it’ll do its job.

My current place we jokingly call the spider house, have a bunch of house spiders around (cats love them) and a few orb-weavers, garden and wolf spiders outside, pretty much anything native isn’t a threat to humans or cats, they do a great job of taking out any pests, rarely see flies inside these days. Spiders and centipedes I’ll leave alone, they’re beneficial to have around.