Ilse received her PhD from the
University of Göttingen. From there she relocated to Bonn to work as a Scientific Assistant at the hereditary biological archive in Bonn. She returned to Berlin in 1931, as a Scientific Guest Researcher at the
Kaiser Wilhelm Institute for Biology in
Berlin Dahlem. She expected to move to Munich to work for the Munich Zoological Institute at the end of 1933, upon invitation by soon-to-be Nobel Prize-winner
Karl von Frisch. However, the discriminatory law “On the Restoration of the Civil Service,” of 7 April 1933 prevented her from doing so on account of her Jewish origins. Ilse instead took up a position as an assistant at the Zoological Institute, alongside which she undertook unpaid work producing educational films. In 1935 she moved in exile to
Britain, where she lived until 1952, teaching biology in schools. She also published articles in
Nature and
Proceedings of the Royal Philosophical Society of Glasgow, and in 1938–39 gave a series of lectures in the
United States of America, supplemented by her scientific films. Ilse resumed her activity as a zoologist between 1952 and 1955, at the
University of Pune, India, where she helped to establish the Zoological Institute. == Research ==