Trout face upstream, so they can only see you if you’re upstream of them – right? Logical assumption, but not right. That might be the case if it were a human facing upstream, but trout have eyes that ...

Jakob von Uexküll was a Baltic German biologist ahead of his time, intrigued by the idea that animals inhabit unique perceptual worlds quite unlike our own. In 1934, he described angling for flies by ...