The first step to long term spider management is to eliminate the ants. You see, the primary food source for the early stages of development for most spiders is the ever present ant and the occasional tasty gnat or drain fly.
From that, they graduate to larger bugs with each instar, or stage of development.
Spiders and scorpions are common pests locally and they are actually beneficial in that they will make a meal of any insect that they can catch!
They are often very difficult to control because they normally stay out of sight during the day and they try to avoid people.
Web spinners use their spinnerets to create bug traps and to make nests or egg sacs that they spin for their offspring.