Bald-faced hornets, scientifically known as Dolichovespula maculata, are social wasps often recognized by their striking black and white coloration. Despite their common name, they are not true hornets but rather a type of aerial yellowjacket. These insects have predominantly black bodies with distinct white markings on their faces, giving them their “bald-faced” appearance. Adult workers typically measure between 1/2 and 5/8 inches in length, while queens can reach up to 3/4 inches.
Geographic Range
Bald-faced hornets are widely distributed across North America, extending throughout the United States and into Canada. They are particularly prevalent in the eastern half of the U.S., with a notable presence in the southeastern regions. This species is absent only from exceptionally dry areas.
Preferred Habitats
Bald-faced hornets thrive in various environments with suitable nesting sites and food sources. They are commonly found in forested areas and woodlands, where trees provide ample locations for their aerial nests. These wasps also adapt well to suburban landscapes and urban parks. The availability of trees, shrubs, and other vegetation, along with proximity to water sources and insect prey, makes these habitats attractive.
Nesting Locations
Bald-faced hornets construct distinctive paper nests suspended from elevated structures. They frequently build these nests high in trees or large shrubs, often at heights of three feet or more. Nests can also be found on man-made structures, including building eaves, sheds, utility poles, and under rock overhangs.
These nests are egg-shaped or pear-shaped, gray, and enclosed, distinguishing them from open-comb nests of other wasps. They are crafted from chewed wood fibers mixed with saliva, drying into a paper-like carton. Nests can reach up to 14 inches in diameter and over 24 inches in length, sometimes as large as a basketball.
Seasonal Activity
Bald-faced hornet activity follows a seasonal pattern tied to their life cycle. A single queen, having survived winter in a sheltered location, emerges in spring, around April or May. She initiates a new colony by building a small nest and laying the first batch of eggs.
As the season progresses, the colony grows rapidly, reaching its peak population in late summer and early fall, often containing several hundred workers. This is when nests are largest and hornets are most visible and active. With the first hard frost, workers and males perish, leaving only newly mated queens to overwinter and start new colonies the following spring.