Social Eavesdropping in Madagascar Hissing Cockroaches (Gromphadorhina portentosa)

Social eavesdropping is when individuals gather information about others by observing social interactions. Insects such as paper wasps learn about the relative dominance status of two other wasps by observing fights. Madagascar hissing cockroaches (MHCs) similarly live in social groups with dominance hierarchies among males and may therefore share this cognitive ability. In the present study, we tested for social eavesdropping in MHCs. Two 120-minutes observation periods were performed to determine how long aggressive interactions between males last. The results showed that the males’ agonistic behaviors lasted an average of 90 minutes, followed by a lack of activity. These findings will lay the groundwork for future studies in which 90-minute trials will be used to observe male agonistic interactions. The next step of this study is to determine whether MHCs are capable of using social eavesdropping to modify their behavior. Before training, 16 males will be randomly assigned as either fighters or observers. During training, two subjects will observe a 90-minute interaction between other males. The observers will then be paired with a fighter they observed and one they did not, and the agonistic behaviors of each will be recorded.