Ants are considered pests when they enter homes and contaminate food. Ants outside are child-friendly insects (with a few exceptions such as fire ants), hard at work foraging and generally oblivious to humans. Ants may be kept as “pets” for observation in ant farms. Thus, the audience is primed to relate to Ant-Man as hero. Yellow jackets are important biological control agents in the ecosystem often preying on herbivores such as caterpillars. On the other hand, yellow jackets can be kept in colonies for observation (but almost no one does). For most people, the good qualities that yellow jackets possess are outweighed by negative interactions. Many people have been annoyed by yellow jackets foraging at fall picnics and more than a few have received a painful sting. Yellow jackets are universally seen as the enemy and the audience is primed to accept Yellowjacket as villain.
Do real life ants and yellow jackets duke it out? Yellow jackets have been observed stinging and feeding on large ants. Ants in numbers can attack and overwhelm a yellow jacket colony. The idea of Ant-Man fighting Yellowjacket has some basis in nature. Unlike the movie, the power of ants lies not in the strength of individuals but in the collective actions of a social group.