PT - JOURNAL ARTICLE AU - Gabriele Valentini AU - Naoki Masuda AU - Zachary Shaffer AU - Jake R. Hanson AU - Takao Sasaki AU - Sara Imari Walker AU - Theodore P. Pavlic AU - Stephen C. Pratt TI - Division of labour promotes the spread of information in colony emigrations by the ant <em>Temnothorax rugatulus</em> AID - 10.1101/791996 DP - 2019 Jan 01 TA - bioRxiv PG - 791996 4099 - http://biorxiv.org/content/early/2019/12/17/791996.short 4100 - http://biorxiv.org/content/early/2019/12/17/791996.full AB - The fitness of group-living animals often depends on how well members share information needed for collective decision-making. Theoretical studies have shown that collective choices can emerge in a homogeneous group of individuals following identical rules, but real animals show much evidence for heterogeneity in the degree and nature of their contribution to group decisions. In social insects, for example, the transmission and processing of information is influenced by a well-organized division of labour. Studies that accurately quantify how this behavioural heterogeneity affects the spread of information among group members are still lacking. In this paper, we look at nest choices during colony emigrations of the ant Temnothorax rugatulus and quantify the degree of behavioural heterogeneity of workers. Using methods from both machine learning and network analysis, we identify and characterize four behavioural castes of workers – primary, secondary, passive, and wandering – covering distinct roles in the spread of information during each emigration. This detailed characterization of the contribution of each worker can improve models of collective decision-making in this species and promises a deeper understanding of behavioural variation at the colony level.