The Sensory Ecology of Ant Navigation: From Natural Environments to Neural Mechanisms

Abstract

Animals moving through the world are surrounded by potential information. But the components of this rich array that they extract will depend on current behavioral requirements and the animal's own sensory apparatus. Here, we consider the types of information available to social hymenopteran insects, with a specific focus on ants. This topic has a long history and much is known about how ants and other insects use idiothetic information, sky compasses, visual cues, and odor trails. Recent research has highlighted how insects use other sensory information for navigation, such as the olfactory cues provided by the environment. These cues are harder to understand because they submit less easily to anthropomorphic analysis. Here, we take an ecological approach, considering first what information is available to insects, then how different cues might interact, and finally we discuss potential neural correlates of these behaviors.

Natural search algorithms as a bridge between organisms, evolution, and ecology

“…Accordingly, most species likely use gradient-climbing as one behavioral "module" (21) in a larger set of sensory-motor responses that, together, generate the long sequences of search behavior needed to locate targets in large spatial landscapes. Other modules may include exploratory behaviors that increase the likelihood that the searcher will encounter sensory cues emitted by a target-for example, the cross-wind casting of insects (21) and seabirds (28)-and memory-based mechanisms for returning to previously visited locations: for example, the path integration-based homing of the desert ant, Cataglyphis bicolor (22). We define the set of behavioral modules a searcher employs and the rules the searcher uses to transition between modules as a natural search algorithm (Fig.…”

“…This will not only help make experiments more realistic, but may also reveal how organisms g., periods of exploration, memory-based homing to known locations (21,22)] to generate flexible sequences of search behavior. We define this set of modules and the rules a searcher uses to transition between them as a natural search algorithm.…”

Ants regulate colony spatial organization using multiple chemical road-signs

“…Outside the nest, ants are known to find their way using a variety of mechanisms including path integration, landmark recognition, magnetic sensing, light polarization, chemical cues and pheromone trails12131415161718. Using cues that are suitable outside the nest for subterranean orientation is not straightforward: the nest's dark environment prevents the use of vision and its complex architecture renders the use of spatial memory unlikely.…”

Private information alone can trigger trapping of ant colonies in local feeding optima

“…The currently accepted model of how ants learn and navigate a route involves holistically learning views along the entire route. When retracing a route, the current view seen by the ant is judged for familiarity against the holistic memory, and the ant turns towards the most familiar view (Baddeley et al, 2011(Baddeley et al, , 2012Knaden and Graham, 2016;Kodzhabashev and Mangan, 2015;Wystrach et al, 2013). Ants can also home towards specific landmarks in an otherwise unfamiliar location (Wystrach et al, 2011;Zeil et al, 2014).…”