"Genus Vespula" is the scientific name of the wasp genus that includes yellow jackets and hornets. Some synonyms for this genus include "paper wasps" (due to the paper-like material they use to build nests), "social wasps" (for their highly social behavior), and "vespids" (a broader term for all wasps in the family Vespidae). In addition to yellow jackets and hornets, other species in this genus include the European paper wasp and the red wasp. Though they can be a nuisance and sometimes even dangerous, these fascinating insects play an important role in the ecosystem and are valued for their ability to control populations of other insects.