Beneficial Because:
Many types of hornets work alone, but the species that get our attention work in organized colonies. Like honeybees, many hornets start the season as small colonies, which increase in size as summer goes on. By late summer, hundreds or thousands of hornets may live in an established nest. But unlike honeybees, which gather flower nectar and pollen, hornets are carnivorous. They feed their young protein in the form of insects gleaned from trees, yards and gardens. Hard-working hornets are especially good at harvesting one and two-day-old caterpillars that are munching on plant leaves. Hornets kill so many smaller insects that organic gardeners should accept them whenever possible.
Food and Habitat:
Nesting sites vary with species, and may be hard to predict. They will eat various soft-bodied invertebrates during spring and summer, and turn to ripe fruits and sugary food in the fall.
Attracting More:
Peaceful coexistence is a worthy goal with hornets. When a nest is found in a location that can be made safe from people and pets, it should be marked or fenced off and left undisturbed. Old nests are vacated in winter, and can be safely handled after a few hard freezes.