Wartime rat control, rodent ecology, and the rise and fall of chemical rodenticides

The story of how World War II stimulated the development of DDT, and the ensuing postwar dependence on such chemical insecticides, is well known. However, less recognition has been given to the wartime efforts to synthesize new rodenticides to fight rat-borne epidemics. Baltimore, Maryland served as the site for field tests of the powerful new compound alpha napthyl thiourea (ANTU) from 1942-1946. This experimental campaign sparked debates over the efficacy of controlling rats via chemical warfare instead of environmental sanitation, which led to the ironic conclusion that urban rat control demanded an ecological, rather than technological, approach.