Faced with uneven terrain, ants often take the fastest, rather than the shortest, route to their destination.
Erik Frank and his colleagues at the University of Würzburg in Germany cleared paths through the grass around nests of a termite-eating ant (Megaponera analis) in Côte d’Ivoire. The ants could walk nearly twice as fast on the paths as on uncleared ground.
Individual scout ants leading raiding parties of several hundred worker ants took the artificial paths on 59% of journeys to attack termites. These routes were longer in distance but demanded 35% less travel time, on average, than a hypothetical direct route through the grass. This is the first time individual scout ants have been documented making complex route calculations.
By minimizing their time outside, ants lower their exposure to attack, the authors say.