  We introduce a simple ecological model describing the spatial organization of
two interacting populations whose individuals are indifferent to conspecifics
and avoid the proximity to heterospecifics. At small population densities
$\Phi$ a non-trivial structure is observed where clusters of individuals
arrange into a rhomboidal bipartite network with an average degree of four. For
$\Phi\rightarrow0$ the length scale, order parameter and susceptibility of the
network exhibit power-law divergences compatible with hyper-scaling, suggesting
the existence of a zero density - non-trivial - critical point. At larger
densities a critical threshold $\Phi_{c}$ is identified above which the
evolution toward a partially ordered configuration is prevented and the system
becomes jammed in a fully mixed state.
