A U.S. War Departments report notes that "in addition to the results of human experimentation much data is available from the Japanese experiments on animals and food crops." German researchers have found that records of the Entomology Institute at the Dachau concentration camp show that under orders of Schutzstaffel (SS) leader Heinrich Himmler, the Nazis began studying mosquitoes as an offensive biological warfare vector against humans in 1942. It was generally thought by historians that the Nazis only intended ever to use biological weapons defensively.