The principal objective of this study was to determine when during the year the control of bandicoot rats would be most cost-effective under the agricultural conditions existing in Bangladesh. An annual cycle in the rise and fall of burrow density was found. This argues for a management strategy directed at reducing rat damage at a specific time period within the year as opposed to a strategy of continuous population reduction. A model predicting rat damage was developed based on monthly estimates of burrow densities in rice and wheat; and projected losses were compared among the four major cereal growing seasons (aman, boro, and aus rice, and wheat). The net benefit of control is predicted to be greatest during the aman rice season in both of the major agroecosystems occurring in Bangladesh.