Lifespan varies greatly across the tree of life. Of the various explanations for this phenomenon, those that involve trade-offs between reproduction and longevity have gained considerable support. There is an important exception: social insect reproductives (queens and in termites, also kings) exhibit both high reproductive outputs and extraordinarily long lives. As both the ultimate and proximate mechanisms underlying the absence of the fecundity/longevity trade-off could shed light on the unexpected dynamics and molecular mechanisms of extended longevity, reproductives of social insects have attracted much attention in the field of ageing research. Here, we highlight current ecological and physiological studies on ageing and discuss the various possible evolutionary and molecular explanations of the extended lifespans of termite reproductives. We integrate these findings into a coherent framework revealing the evolution of longevity in these reproductives. Studies on termites may explain why and how ageing is shaped by natural selection. This article is part of the theme issue 'Ageing and sociality: why, when and how does sociality change ageing patterns?'
