Naked mole-rats live in colonies of two breeders and around 300 non-breeding workers. Although the breeding pair carries the metabolic cost of reproduction and, in the queen’s case, lactation, they live longer than non-breeders and remain fertile throughout their lives. Researchers at the Leibniz Institute on Aging in Germany investigated the genetic mechanisms beneath this apparent paradox. Their findings are published in the open access journal BMC Biology.