When one stings, that also causes the others to become excited. If bit, run. Go indoors or jump into water. Insects have a hard time following a person through a thicket of woods. Insects are repelled by the odor of turpentine.
Stinging insects prefer dark colors.
So wear white or light-colored clothing. Do not wear perfumes of any kind. Insects are attracted to people who are deficient in zinc. Take at least 60 mg a day. Sometimes brewer's yeast or garlic rubbed on the skin deters insects.