Behavior Yellowjackets, in particular, may be late season pests around picnics, trash cans, and humming bird feeders as they scavenge. The only way to control this situation is to locate and destroy the nest, which is rarely possible. As an alternative, keep all outdoor food and drinks covered, except while actually eating. Bee guards or a coating of petroleum based chest rub can be used on hummingbird feeders where the insects land. Trash cans should be kept covered or have a flap over the opening.
Defensive behavior occurs in response to nest defense.
If the nest is not in the immediate vicinity the likelihood of stings is greatly reduced. The first decision to make is whether control is actually necessary. They also serve as food for other bears, skunks, birds, and other insects. Unlike honey bees, hornet and yellowjacket colonies die out each year. If a hornet nest is built high in a tree, you may choose to simply wait until the colony dies out in late fall or early winter.