European Wasp 

The European Wasp is now a well established urban pest in eastern and southern Australia. 
It has a more direct flight path than domestic bees and unlike them will sting repeatedly if provoked.

 Interestingly, there are few occurrences of European Wasp sting recorded, since I guess no one is stupid enough to disturb the paper nest when spotted. Many local councils will remove the nest if spotted (for a fee, generally). 

The European Wasp loves sausages on a barbeque, drink cans and pet food left out. 
They are attracted to water in summer and if you spot more than 20 at a time in any location, it means you are within 20 metres of their nest. A nest lasts a year and control is to spray carbaryl, but to be covered while doing so, or expect to be attacked. 
Most effective spraying is done at night or on a cold day when activity is minimal.

European Wasp Nest	European Wasp