JOIN USThe research has shown that Argentine ants (Linepithema humile), do not just retrace their steps when presented with a barrier—as might be expected Instead, the ants begin a localised search that seems to take into account the direction in which they were planning to go, reports Nature.
Many computerised systems, such as those that route telephone calls through busy networks while minimising connection times, already solve shortest path problems by deploying virtual ants. These ants explore all possible routes in a system and deposit virtual pheromones on each route they travel. “I figured Argentine ants had to have some way of dealing with obstacles that didn’t involve starting a search from scratch,” says Chris Reid, of the University of Sydney.
To put the insects to the test, Reid and colleagues presented them with a logic puzzle known as the Towers of Hanoi. The human version of the puzzle comprises three rods with a number of differently sized rings. The rings have to be stacked so that the smallest is on top and the largest on the bottom, without even lifting more than one ring at a time or ever placing a larger ring on top of a smaller one.
“The discovery that these ants can solve the Towers or Hanoi is far from trivial,” said Simon Robson, of James Cook University. The discovery has indicated that Argentine ants use more than just simple trail pheromone to find their way.