While they are similar to other insects in some ways, you can identify a yellow jacket using the insect's size, color and behavior. Yellow jackets are small insects, typically under an inch long. The name derives from the alternating bands of black and bright yellow on this species' abdomen. Unlike similar-looking insects, yellow jackets nest exclusively underground, and they defend their nests readily and aggressively.
Compared with similar insects, yellow jackets are not particularly large. At an average of 1 inch in length, they are about the same size as a typical honey bee. However, while honeybees are fuzzy and have golden stripes, yellow jackets have relatively smooth bodies and brilliant yellow stripes. European paper wasps have very similar color patterns to yellow jackets, but these insects have longer, thinner bodies and nest above ground.
Yellow jackets are one of the few wasp species that nest underground. Bald-faced hornets, which are closely related to yellow jackets, also nest underground and are highly aggressive, but they are black and white as opposed to black and yellow.
Many bumblebee species also nest underground, but these nests are home to only a few individuals, while yellow jacket nests can have thousands of members. Digger wasps, such as mud daubers and some spider wasps also nest underground, but these wasps lead solitary lives and are not aggressive.