Everything bites

I have been in Australia for about 9 days and I have a constellation of mosquito bites on my lower back, a few scattered around my elbow and legs, and a large spider bite on my ankle. While I haven't noticed lots of insects, except for a few biting flies in Melbourne, I apparently can't even sit in a chair without getting bitten by some strange insect or another. Since I haven't died yet, and none of my limbs have blackened and fallen off, I apparently haven't been bitten by anything too poisonous. But in a country with the top ten most poisonous snakes in the world, and only slightly less venomous spiders, it's not reassuring to know that I am a flesh-eating-insect-magnet. However, as a kindly woman told me when describing the poisonous Whiteback spider, whose venom permanently kills off the skin and/or muscle at the site of the bite, you don't really need to worry unless you've been bitten.