IrishDude, no need to worry too much about the snakes and spiders in the cities. If you see a snake in the city i'd be very suprised and even if you did it would probably turn the other way and run (not that snakes run as such
You are more likely to see spiders (Red Backs
, Funnel Webs
) but again its not something i would be too worried about. Its usually a matter of stay away from them and they'll stay away from you.
If you go bush then obviously you will come across snakes and spiders more often but I wouldn't let it concern you too much at all.