There are several races of domesticated honeybees with varying characteristics of honey production, disease resistance and gentleness. Since the honeybee will die after stinging, there is no advantage for a bee to sting to defend itself. Honeybees will generally only sting when the hive is directly threatened. Honeybees found in the field or on a flower will rarely sting.
Note: Americanized honeybees can be more aggressive than the more common European honeybees, but still only defend the hive.
Yellow jackets are carnivorous during the brood rearing part of the season. They feed insects to their brood, and obtain the sugar for their flight muscle energy mostly from secretions of the brood. During this time they can be attracted to traps baited with meat or fish. Near the end of summer, when brood rearing ceases and this sugar source is no longer available, yellow jackets become frantic for sugar, and can be baited with sugar based baits. They are also much more likely to visit fall flowers for nectar, than they are earlier in the season.