In [Don4], we described a manipulation task for cooperating mobile robots that can push large, heavy objects. There, we asked whether explicit local and global communication between the agents can be removed from a family of pushing protocols. In this paper, we answer in the affirmative. We do so by using the general methods of [Don4] analyzing information invariants. We discuss several measures for the information complexity of the task of pushing with cooperating mobile robots, and we present a methodology for creating new manipulation strategies out of existing ones. We develop and analyze synchronous and asynchronous manipulation protocols for a small team of cooperating mobile robots that can push large boxes. The protocols we describe have been implemented in several forms on the Cornell mobile robots in our laboratory.