why does everything have to "symbolize" anything? spiders are cool. they help to control populations of other insect pests. they, like all preditors, are an indication of the presence of their prey. everything goes where there is an environment for it. where you see spiders in real life, if the're inside your home instead of someplace outside of it, this is an indication of a need to do something to make your home less inviting as an environment for their prey, i.e. ants, roches, that sort of thing, which generaly means a need to keep things extra clean for a while, at least untill the problem goes away. well that is spiders in the waking world. spiders in dreams i don't know. i think that would depend entirely upon how you personaly perceive them in a mythic sense. or it might be something you picked up from the expressed perceptions of others. if you're looking for rote answers on symbolism, there are a zillion books that will give you that. a concept i seriously question the usefulness of, but if that's what you're into, go for it i guess. =^^= .../\...
Since many are scared of spiders, they may symbolised things hidden and kept secret, perhaps secret enemies. Most books say that unless you killed them, that it is a "bad" omen. You'll just need to start your own dream dictionary by correlating what happens in real life with what happened in the dream.
No book, nor any person (regardless of level of knowledge and understanding of dream interpretation), can ever tell you what anything, of any kind, symbolizes in your dream. I don't mean this to sound harsh at all . I simply mean no two people will ever associate the exact same emotions with any range, amount, or catagory of elements, objects, or other emotions. Ever. I personally love spiders. Why would they represent a hidden evil, or some kind of malice? Simple, because they don't. They represent what you believe them to represent. The context in which the object takes place holds the symbolization, not the object. Blessed be! <33