  Foraging, either solitarily or collectively, is a necessary behavior for
survival that is demonstrated by many organisms. Foraging can be collectively
optimized by utilizing communication between the organisms. Examples of such
communication range from high level strategic foraging by animal groups to
rudimentary signaling among unicellular organisms. Here we systematically study
the simplest form of communication via long range repulsive interactions
between two diffusing Brownian searchers on a one-dimensional lattice. We show
that the mean first passage time for either of them to reach a fixed target
depends non-monotonically on the range of the interaction and can be optimized
for a repulsive range that is comparable to the average spacing between
searchers. Our results suggest that even the most rudimentary form of
collective searching does in fact lower the search time for the foragers
suggesting robust mechanisms for search optimization in cellular communities
