On opposite shores of a continent separated by four thousand kilometres of open ocean, two unconnected populations of bottlenose dolphins have arrived at the same ingenious solution: using large seashells as traps to catch sheltering fish. The recent documentation of this 'shelling' behaviour in Queensland's Hervey Bay, long known only from Western Australia's Shark Bay, invites us to consider how intelligence, shaped by similar pressures and opportunities, can converge on identical inventions without any shared instruction. It is a reminder that culture — the slow passage of hard-won knowledg