Biology
Yellow jackets, hornets and other wasps are Vespids (Family Vespidae), a group of some of the more dangerous of the stinging insect pests. Yellow jackets are among the smallest of this group of stinging insects. These pests are social, building nests that can be quite large. Nests are made from a material called carton or paper. This material is produced by females who combine their saliva excretions with wood fibers to form the familiar looking paper nest.
A paper nest can be built by hornets, paper wasps and yellow jackets, but the yellow jacket nest is usually not visible. This nest is usually underground but there are many cases where these insects have built nests above ground in the wall voids of homes.