Advances in Rodent Control

B, 'EFORE THE WAR our three most useful rodent poisons were imported. Red squill came from the Mediterranean Sea area. Strychnine came from India and French Indochina. Thallium sulfate came from Germany, France, and Belgium. Hostilities cut off almost all those sources at the time that the armed forces were planning and executing the Pacific campaigns that sent our troops into areas where many strange rat-borne diseases existed. Other factors added to the urgency: Rodents destroy crops, and there was great need of food ; in many theaters of war we had concentrations of men and supplies, which were prey to attack by rats and mice; there were contacts with species and populations of rats not previously encountered by great numbers of human beings. The shortage of effective rat poisons was extremely serious. A start had been made in the search for substitute materials. Two independent groups had intensified their efforts and each had made progress. Curt P. Richter, of Johns Hopkins University, had discovered the toxicity to laboratory rats of ANTU, or alphanapthylthiourea. The Fish and Wildlife Service, of the Department of the Interior, at its Wildlife Research Laboratory in Denver, studied a number of promising compounds. When the emergency appeared to be acute, the value of the research programs was recognized by the Office of Scientific Research and Development, and funds were provided to put them into high gear. The accomplishments that resulted were distinctly a product of war, but they are now available to enhance the peacetime welfare and economy. ANTU soon was produced in quantity adequate for widespread testing, and, at Dr. Richter's request, the Fish and Wildlife Service entered into cooperation with his group to determine the value of the new poison for the control of both rats and field rodents. Although ANTU killed