In this paper, we consider using angle of arrival information (bearing) for network localization and control in two different fields of multi-agent systems: (i) wireless sensor networks; (ii) robot networks. The essential property we require in this paper is that a node can infer heading information from its neighbors. We address the uniqueness of network localization solutions by the theory of globally rigid graphs. We show that while the parallel rigidity problem for formations with bearings is isomorphic to the distance case, the global rigidity of the formation is simpler (in fact identical to the simpler rigidity case) for a network with bearings, compared to formations with distances. We provide the conditions of localization for networks in which the neighbor relationship is not necessarily symmetric.