Every colony of E. ruidum simultaneously maintains individuals
that collect the same type of food item, but with two distinct
foraging strategies. Workers of these foraging types are behaviourally
distinct from one another but rely upon a common pool of
food resources. The disparate behaviours that make up these two
strategies effectively serve to repartition the original pool of resources
gained during primary foraging. The first foraging strategy
is ‘normal’, with workers that collect food from within their territories.
These individuals find food within the home range, walk in a
straight line back to the nest, encounter other ants along the way,
interact with them, and carry on in a nonchalant fashion. The
second foraging strategy is thievery, in which workers collect food
from inside a colony that is outside their own colony's home range.
These individuals walk more slowly, pause more frequently and
avoid encountering conspecifics en route. These individuals are also
more prone to reverse direction when perturbed and to drop their
pilfered food items when grabbed.