you can find house spiders in houses it alll depends where you live.
There are probably about a hundred thousand different small black spiders on Earth.
Spiders do not do anything that would hurt any kind of plant. Spiders are carnivores, and most of the time they eat insects. Some spiders eat a little plant pollen, and some spiders drink nectar from flowers, but they don't damage anything by so doing. Other than walking over plant life, or attaching webbing to branches or leaves, they do not interact with plants.
orb spiders
trapdoor spiders
Tree braches and bamboo
aracnids
the anchient spiders and the browns recluse.
Any quality spray, such as Olive Oil.
It is called Arachnophobia- scared of spiders
I do not know of any spiders that do not eat flies.
arachnids