In the 1850’s, the naturalist Henry Walter Bates found a certain set of butterflies who were clearly not of the same species but whose wings looked almost the same to the naked eye. After thinking it over, Bates eventually figured out what was going on: While the butterflies which were toxic to potential predators (the “models”) were able to operate freely and relatively unmolested, there had also developed a “mimic” population of butterflies which wasn’t toxic at all, yet still went untouched!

Source: https://www.farnamstreetblog.com/2016/12/batesian-mimicry/