Just follow your nose: homing by olfactory cues in ants

How is an ant - equipped with a brain that barely exceeds the size of a pinhead - capable of achieving navigational marvels? Even though evidences suggest that navigation is a multimodal process, ants heavily depend on olfactory cues - of pheromonal and non-pheromonal nature - for foraging and orientation. Recent studies have directed their attention to the efficiency of pheromone trail networks. Advances in neurophysiological techniques make it possible to investigate trail pheromone processing in the ant's brain. In addition to relying on pheromone odours, ants also make use of volatiles emanating from the nest surroundings. Deposited in the vicinity of the nest, these home-range markings help the ants to home after a foraging run. Furthermore, olfactory landmarks associated with the nest enhance ants' homing abilities.

► Ants use pheromonal and non-pheromonal volatile chemicals for homing. ► Pheromone trail networks enable ants to exploit resources flexibly and efficiently. ► Volatiles deriving from the nest and/or its surroundings facilitate the ants' homing. ► Olfactory landmarks associated with the nest enhance ants' homing abilities. ► Homing ants benefit from combining olfactory and visual landmarks.