I’m fond of this paper because it's my first ecology paper. If you've been reading this far, you know that I'm all about stereo vision - its properties, neuronal basis, cortical location and so on. This paper, in contrast, is about predator-prey relations, e.g. a sparrow trying to avoid being eaten by a cat or a hawk. Needless to say, the ecology in this paper comes from the other authors. My contribution was to help with the mathematical modelling. Ben Brilot, the first author, and his PI Melissa Bateson (another Royal Society University Research Fellow before she became a Reader here at Newcastle), are interested in anxiety and wariness in animals. In this project, they and our colleagues Daniel Nettle and Mark Whittingham were interested specifically in how a prey animal's optimal behaviour changes if it has to avoid not one, but two or more predators which place conflicting demands on the animal. If the overall danger level rises, should the animal simply become more wary to every potential threat, or should it target its wariness towards the greater danger? We thought that signal detection theory could be a useful framework, and Ben and I spent a lot of time sitting down together trying to figure out how to make that work. As ever, the issue was how to simplify the problem enough to make progress while still retaining enough complexity to make it interesting. I think we both found it a really interesting experience. I was fascinated to get this insight into my ecological colleagues' field, and blown away by the depth and breadth of their knowledge across so many species and situations.