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The bald-faced, or white-faced, hornet, widely distributed throughout North America, is about 3 cm (about 1.2 in) long and is black with white markings on most of its segments and on its face. Its gray nest is usually suspended from a tree limb. Yellow jacket is a name applied to a number of species that have extensive yellow markings. Yellow jackets construct their nests close to or under the ground; a single nest may contain up to 15,000 individuals. Yellow jackets are often found near humans, and their sting can be serious for people sensitive to their venom, or if a person is stung many times simultaneously.
The European hornet first appeared in the eastern United States about 1850. This hornet is reddish brown streaked with yellow and attains a length of more than 2.5 cm (1 in). Its brown nest is built in hollow trees, in rock crevices, or on human structures. Like the smaller hornet species, it eats insects and their larvae and ripe fruit.
In several hornet species, no workers are produced. Instead the female lays its eggs in the nests of other wasps, where the eggs hatch and the young are fed.
Scientific classification: Hornets belong to the family Vespidae, of the order Hymenoptera. The bald-faced, or white-faced, hornet is classified as Vespula maculata. The European hornet is classified as Vespula crabro.