Corals that look dead may be able to recover, according to research that offered a glimmer of hope to the world’s reefs. Corals are made up of thousands of tiny creatures called polyps. If the water is too warm, these polyps die, which leads to coral bleaching. But research from the University of Barcelona published in Science Advances in October found that some polyps shrink and abandon their skeleton before recolonising a new one when conditions improve. The survival strategy will not, however, be enough to rebuild the world’s reefs if warming continues at its current rate.