Rodents cause substantial pre-harvest losses to a wide range of crops in Southeast Asia and Australia. They also consume and contaminate stored grain and are vectors for disease of humans and domestic livestock. Rice is the major food crop in Vietnam and it suffers high damage from rat species, particularly in the Mekong Delta Region. Loss of production spread across 10 provinces is estimated to be between 300 000 and 400 000 tonnes. This small project will focus on factors determining rodent population growth and methods to manage this growth. The research aims to develop better integrated pest management of rodents and to promote methods that do not affect the environment as alternatives to the current methods which rely heavily on the use of chemicals.