Yellowjackets may be confused with other wasps, such as hornets and paper wasps such as Polistes dominula. A typical yellowjacket worker is about 12 mm (0.47 in) long, with alternating bands on the abdomen; the queen is larger, about 19 mm (0.75 in) long (the different patterns on their abdomens help separate various species).
Yellowjackets are sometimes mistakenly called "bees" (as in "meat bees"), given that they are similar in size and general coloration to honey bees, but yellowjackets are actually wasps. In contrast to honey bees, yellowjackets have yellow or white markings, are not covered with tan-brown dense hair on their bodies, and do not have the flattened, hairy pollen-carrying hind legs characteristic of honey bees (although they are capable of pollination).
Yellowjackets have lance-like stingers with small barbs, and typically sting repeatedly, though occasionally a stinger becomes lodged and pulls free of the wasp's body; the venom, like most bee and wasp venoms, is primarily dangerous to only those humans who are allergic or are stung many times. All species have yellow or white on their faces. Their mouthparts are well-developed with strong mandibles for capturing and chewing insects, with probosces for sucking nectar, fruit, and other juices. Yellowjackets build nests in trees, shrubs, or in protected places such as inside man-made structures, or in soil cavities, tree stumps, mouse burrows, etc. They build them from wood fiber they chew into a paper-like pulp. Many other insects exhibit protective mimicry of aggressive, stinging yellowjackets; in addition to numerous bees and wasps (Müllerian mimicry), the list includes some flies, moths, and beetles (Batesian mimicry).
Yellowjackets' closest relatives, the hornets, closely resemble them but have larger heads, seen especially in the large distance from the eyes to the back of the head.
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