Throughout the summer months, it is not uncommon for humans to have close encounters with yellow jackets as they use lawn mowers, edging tools or any other lawn equipment that makes noise.  The sounds made by various lawn tools will anger and disturb yellow jackets in the immediate area.  Yellow Jackets are often mistaken for honeybees. 

Yellow jackets 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. 
A yellow jacket nest resembles a hornet nest and can be inhabited by thousands of workers.  In most areas of the country, the majority of the pest population does not survive the cold winter months.  In parts of Florida and California it is not uncommon to find perennial nests that live throughout the entire year.  This situation creates even larger colonies in the nests, which is a great hazard to the unsuspecting person or family dog that ventures too close to the nest or nest entrance.

The German yellow jacket is another stinging insect that is often found in attics, crawl spaces, inside hollow blocks or other voids of homes in the northeast United States.  German yellow jackets found in other areas of the United States usually nest beneath the soil, in ground burrows or nests.