Contrary to the common characterization that polygyne ants are non-aggressive to one another, the research team found consistent aggression occurred between particular pairs of colonies. Aggression was still clearly lower than that expected in monogyne fire ants, where every colony is aggressive to every other colony. The pattern of aggression among colonies is represented in the dendrogram. Aggression level was unrelated to the distance between colonies. Researchers suspected that since polygyne colonies are formed when older colonies split into two, nearby colonies were more likely to be relatives and therefore less likely to be aggressive.
Colonies tend to become more aggressive to each other during the time of the experimental trials.
The research team compared the aggression level between pairs during the first trial with that during the second. UH researchers found that, overall, colonies had a significantly higher level of aggression during the second trial than the first, but that this increase in aggression level was driven by the most aggressive colonies. Colonies which were more aggressive to start with became even more aggressive, while the least aggressive colonies showed little change. Although polygyne colonies are related to each other, they will not be genetically identical because of the unequal contribution of the multiple queens. This may favor competition over cooperation during the period most favorable for reproduction.