This atypically large black-and-white yellowjackets gets its common name of baldfaced from its largely black color but mostly white face and that of hornet because of its large size and aerial nest. Baldfaced hornets are found throughout the United States.
Adult workers about 5/8"-3/4" (15-20mm) long queens about 3/4" (20mm). Color black and white pattern on most face as 2 angled stripes on thorax towards head and on last 3 abdominal segments. Head with clypeus (upper lip) broadly truncate slightly notched at apex. Hind wing without jugal lobe (lobe on rear near body). Pronotum in lateral view almost triangular extending to tegulae (structure at base of front wing) or nearly so. Middle tibia with 2 apical spurs. Builds paper enclosed aerial nest grey in color.
The overwintering queens selects the nest site. This can vary from shrubs or vines at ground level to 66 ft (20 m) or higher in trees. Nests may also be built on overhangs utility poles houses sheds or other structures. Nearly all nests are constructed in exposed locations. At maturity the nests can be quite impressive with sizes of up to 14" (35 cm) in diameter and over 24 (60 cm) in length.