m different colonies of most social insects generally involves aggression. Such behaviors are adaptive: It is advantageous for workers to aid their own kin and discriminate against non-kin. Aggressive behaviors usually occur when one ant possesses recognition cues not shared by members of a given colony (Errard 263-270). The recognition systems of many invertebrate and vertebrate species are mediated by olfactory cues. Similarly, it is widely believed that nestmate recognition in social insects also involves the sense of smell (Obin & Meer 1361-1368). Various early investigations noted that ants were accepted as nestmates or attacked based on their odor. Researchers found, for example, that chloroformed ants were accepted by their nestmates. In addition, ants which had been smeared with the blood of foreign ants of the same species were found to be attacked. Conversely, foreign ants that were washed and then smeared with the blood of colony ants were generally recognized as nestmates. Such studies demonstrated that there was "a superficial difference between ants from different colonies which could be easily removed or overlain" (Sudd 117-119).
Regardless though, communication in ant societies could be based on multicomponent signals. These probably involve "nested levels of variation in chemical and other cues (H÷lldobler 19-21)." For example, in addition to odor, body shape and movement might also influence recognition behaviors (Sudd 117-119).
Of the different cues, however, the most important are probably chemical in nature (Topoff & Zimmerli 484). These substances are thought to be simultaneously specific and anonymous. Thus, while workers are able to discriminate between nestmates and intruders, they also treat all nestmates alike. Although individual ants within a colony may possess genetic variations, they are not recognized as being different (H÷lldobler 19-21).
The actual sources of these nestma...