^ abOther hornet species (those not European hornet) have a more toxic sting, and are more aggressive.
^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.
^Since the barbed stinger evolved as a colony defence against vertebrates, the invariable outcome of stinging a mammal or bird is that the stinger becomes lodged in the victim's skin and tears free from the honey bee's body, leading to her death within minutes. As such, there is rarely any evolutionary advantage for a bee to sting a mammal to defend itself as an individual; honey bees will generally only sting when the hive is directly threatened, and honey bees found in the field or on a flower will rarely sting. Note: Africanized honey bees can be more aggressive than the more common European honey bees, but still only defend the hive, and their sting is the same.
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