European wasps like sweet foods and meat - this is why they appear at barbeques. Unlike bees, they do not collect pollen from trees and flowers. European wasp nests have thousands of wasps. They can each sting many times.
If you can see lots of wasps flying around your property, there is probably a nest somewhere. They usually fly within 50m to 200m from their nest and are more common in summer.
You can find nests in the ground, in rubbish heaps or at the bottom of trees and shrubs. You can also find them in roofs, walls and under the eaves of houses. Nests are usually light grey and look like cardboard. They are usually football-sized or larger and you can see a 2cm to 5cm-wide entrance.
The wasp does not have natural predators in Australia to control them, and the warmer climate means wasps survive longer.