A new study using data from earlier work that had generated conflicting results now reveals that bacteria do indeed age, but aging and rejuvenation occur simultaneously. Aging appears to be related to inheritance of the old pole. When a bacterium divides, each progeny receives an old (pre-existing) pole and a new pole, which is created during division. When the progeny divide, both daughter cells will receive a new pole from this division cycle, but one cell will have the old pole from the original ancestor, whereas the other will receive the former new pole. By using a modelling approach, the investigators now show that cells with the older poles grow more slowly than cells with the newer poles. As a result, the older poles would be gradually lost and the population would be dominated by newer poles. The authors speculate that the damage associated with the older poles slows bacterial growth, and that by receiving newer poles, the bacteria can rejuvenate.