Often times bees will hide nests under eavesdropping, under stairs, inside BBQs and in trees. All wasps will defend their nests, but the Yellow Jackets and hornets are the most aggressive. They can be distinguished from bees by their thin "waists." Bees are thick-waisted. They fold their wings lengthwise when at rest. The yellow jacket colony will remain active for only one summer, after which the queens will fly away to start more colonies. The remaining ones, die at the end of the summer, the nest is not reused.