How to navigate without maps: The power of taxon-like navigation in ants

Rodents are said to have two different navigational systems, a map-like locale system and a route-based taxon system consisting of sensorimotor routines such as beaconing and turns at appropriate stimulus conditions (motor routines). Ants on the other hand are not known for map-like navigation, and seem to get by with a repertoire of taxon-like strategies. I review how this repertoire serves ants in making up for the lack of a locale system. Path integration — keeping track of the straight-line distance and direction from the starting point — operates continuously in the background, and can be called upon as necessary, or relied on in habitats in which no useful visual cues are available. Crucial to the power of a taxon-like repertoire is using the full panoramic visual context, both to guide the operation of strategies (context-modulated servomechanisms) and to guide navigation directly. The entire repertoire is backed up by systematic search strategies. I end with some reflections on the power of taxon-like strategies.