There are four common species of yellow jackets in Ontario. The German yellow jacket is the most frequent pest
species and also makes the largest nests, with a possibility of more than 3000 wasps in a colony.
In spring a new colony is established by the queen in a hollow stump, below ground in a cavity,
in a wood pile even a hollow tree, or other protected voids such as an attic.
The actual nest has many layers (combs) that are surrounded by paper, which is made from wood fibres.