Grant is a principal scientist at the International Rice Research Institute and an expert on rodent biology and management. He has authored or co-authored over 200 scientific papers, six books on rodent ecology and management, and one book on impacts of natural resource management in lowland rice. He has also written 80 non refereed proceedings of conferences. He is the coordinator of the Irrigated Rice Research Consortium (IRRC) from 2005 to present, funded by the Swiss Agency for Development and Cooperation (SDC). The IRRC focuses on natural resource management (NRM) of rice production in the irrigated agricultural lowlands in 11 Asian countries. Under the IRRC umbrella for partnerships, Grant is the coordinator of the Closing Rice Yield Gaps in Asia with Reduced Environmental Footprint (CORIGAP) Project, funded by SDC and located in six Asian countries.