Vision for navigation: What do you need and how do you use it?

The visual systems of animals are used to provide information that can guide behaviour. In the cases where insects demonstrate impressive visually-guided behaviour we might reasonably ask how the low-resolution vision and limited neural resources of these insects are tuned to these successful behavioural strategies. Such questions are of interest to both biologists and to engineers seeking to emulate insect-level performance with lightweight hardware. One behaviour that insects share with many animals is the use of learnt visual information for navigation. Ants, in particular, are expert visual navigators. Across their foraging life, ants can learn long idiosyncratic foraging routes. What’s more, these routes are learnt quickly and the visual cues that define them can be implemented for guidance independently of other social or personal information. Here we review the style of visual navigation in ants and consider the mechanisms that underpin it. Using historical and modern evidence we can sketch out the 'known-knowns' and 'known-unknowns' based on a perspective that robust navigation comes from the interaction of behavioural strategies, visual mechanisms and neural computation.