The bald-faced hornet is only found in North America. This insect (Dolichovespula maculata) is not a true hornet, but is actually a large, black and white wasp, closely related to the yellow jacket wasp.

These hornets are social insects and live together in colonies. Over-wintered mated females (queens) start the colonies by building a nest and laying a first set of eggs. One or more broods of workers, infertile females, are produced, and the colonies increase in size during the summer. The workers can be identified by the large patches of white on their faces, resembling a bald spot, hence their name, the bald-faced hornet. The nest can contain hundreds of individuals and a queen, who stays deep in the middle of the nest, protected by her workers. When winter comes, all, except the new queens, die off in the cold weather.

The nests of bald-faced hornets are usually large, grey structures with a pointed end like a football. Like the homes of other wasps, their nests are made from a paper-like material made from wood fibres, collected from various sources, mixed with saliva. The nests normally have half-circular shaped patterns on them, and inside the nest contains many series of cells. The aerial nests can be found hanging attached to trees, bushes, low vegetation and buildings.

Bald-faced hornets do not like to be disturbed, and will defend themselves by stinging, which be very painful. Unlike the honeybee, their stinger is not barbed, but is straight and smooth, allowing them to sting repeatedly. An attack from a swarm can be life threatening.

In terms of pollination, bald-faced hornets will visit flowers frequently for two reasons. They drink flower nectar for quick energy while they hunt, and they use flowers as a hunting ground for smaller insects that are also attracted there. In fact, several kinds of wasps are beneficial in gardens, since they are predators of insects that damage plants.