Wildlife Damage Management, Internet Center for


Date of this Version

December 1979


Rodenticides have become the "standard" for rodent control, and Anti-coagulants have been the quid pro quo. For three decades warfarin(and other dicoumarols) and then the indandiones have been the control element for commensal rodents. However, excessive and indiscriminant uses have selected for resistant populations of Norway rats, roof rats, and house mice in many parts of the U.S. (Jackson and Ashton, 1979). Though resistance is often referenced to warfarin, it is a cross-resistance to all of the currently available, "first-generation" anticoagulants.