Do animals have insight, and what is insight anyway?

We cannot test animals for insight's distinctive phenomenology, the "aha" experience, but we can study the processes underlying insightful behaviour, classically described by Köhler as sudden solution of a problem after an impasse. The central question in the study of insightful behaviour in any species is whether it is the product of a distinctive cognitive process, insight. Although some claims for insight in animals confuse it with other problem-solving processes, contemporary research on string pulling and other physical problems, primarily with birds, has uncovered new examples of insightful behaviour and shed light on the role of experience in producing it. New research suggests insightful behaviour can be captured in common laboratory tasks while brain activity is monitored, opening the way to better integration of research on animals with the cognitive neuroscience of human insight.