LifeWhaleworld: Looking for cetacean culture Orca clan calls and dolphin "tail-walking" provide clues to cetacean culture, find Hal Whitehead and Luke Rendell in The Cultural Lives of Whales and DolphinsCultureLab
HealthThe mystery of yawning: We all do it, but why? Hot, tired brains and an excess of stress hormones. Could these be the reasons why we yawn, asks neuroscientist Simon ThompsonOpinion