Wasps (yellow jackets)

Yellow jackets are social hunters living in colonies containing workers, queens, and males. They measure 10 to 25mm long and are yellow and black stripped.
Nests are built in trees, shrubs, or in protected places such as inside human-made structures (attics, hollow walls or flooring, in sheds, under porches, and eaves), or in soil cavities, mouse burrows, etc. Nests are made from wood fibre chewed into a paper-like pulp.
They can persist as long as they are kept dry. Yellow jacket nests usually last for only one season, dying off in winter. In the spring, the cycle is repeated (spring weather is the most important factor in colony establishment).

It is primarily dangerous to those who are allergic, unless a victim receives a large number of stings.