For us humans, one paper wasp (Polistes fuskatus) is practically no different from another. However, there are such differences and, as it turned out, representatives of the same species perfectly distinguish between their fellows.
Scientists at Cornell University (USA) have found that this unique ability in paper wasps was formed in the process of evolution within only a few thousand years. For other insects, it took hundreds of thousands and even millions of years.
In 2002, during an experiment, researchers changed the appearance of some wasps with the help of paint, as a result of which these individuals became like strangers to their relatives and received from them a "portion" of increased aggression. However, after some time the level of aggression began to decrease, which, according to scientists, was obviously a consequence of the habituation of "normal" wasps to "painted" ones, which again became "their own" for them.
Among insects, this behavior is an absolute phenomenon. Scientists were convinced of this by analyzing the genome of paper wasps and comparing it with the genome of their closest relatives Polistes metricus and Polistes dorsalis, which lack such super skills. Moreover, such pronounced cognitive changes in paper wasps (unlike other species) have formed in just the last several thousand years.
Something similar is typical for some species of bees and wasps, in whose families there are several "queens". In such communities, a certain hierarchy is formed, accompanied by an intraspecific struggle for power. Probably, it is precisely such conditions that lead to the fact that you need to know your opponent by sight.