The history of introduction of Rattus species onto Pacific islands and their management are discussed. The Polynesian rat was transported among inhabited islands by Micronesians and Polynesians in their outrigger canoes. The larger roof rat was less widely distributed prior to World War II, and where resources are limited, locally it may push the Polynesian rat to extinction. The Norway rat does poorly in most tropical areas and is restricted to warehouse, dock, or residential areas. At Eniwetok Atoll in the Marshall Islands, Polynesian rats were probably the only rodents present until after WW II, when roof rats were brough in along with supplies and equipment for the atomic testing program in the late 1940s or early 50s. It is speculated that Polynesian rats were exterminated by the atomic blast that denuded the island, while roof rats likely survived within protected cable tunnels or under concrete structures.