Octopuses and squid are close cousins with much in common. Both groups are remarkably brainy molluscs, especially compared to their relatives including snails, clams and slugs. They have complex nervous systems which, among other things, intricately control their colour-changing skin. A recent study of Humboldt squid suggested they have a simple language of patterns displayed across their bodies. Another piece of research on oval squid in Japan has recently shown that, just like octopuses, squid can also match their body colour to their surroundings to hide from predators.