Animal longevity widely differs across species, and even individuals from the same species may exhibit different rates of ageing. In different species, the rate at which individuals actually age is related to the level of their social interactions, but this was still not known in ants. In a given colony, ant individuals are close genetic relatives, exhibit very different behaviours and a contrasted lifespan according to the Caste. Such characteristics constitute main advantages to study relationships between sociality and ageing. Therefore, the aim of this study was to characterize differences in the proteome of Lasius niger queens versus that of domestic and foraging workers. Proteomic data were put in relation with the behaviour of individuals from the three Castes. Hence, it was found that sociality correlates with ant longevity, with i) social immunity enabling the queen to mainly invest in soma protection, and ii) marked exposition of workers to the environment and nutrients inducing metabolic pathways that reduce their lifespan.