In this military training film, the use of DDT (dichlorodiphenyltrichloroethane) as an insecticide and larvicide is explained. The first sample of DDT was submitted to the U.S. Department of Agriculture's Bureau of Entomology and Plant Quarantine, Division of Insects Affecting Man and Animals in November 1942 for evaluation. It was found to be effective in small quantities when mixed with fuel oil and spread over a large area. DDT affects the nervous systems and motor coordination of insects.The proper ways to handle pure DDT concentrate in powder form, to mix the powder with fuel oil, and to mix the powder with a dry medium (flour, road dust, etc.) are shown. The most efficient methods of spraying DDT in solution or powder are illustrated by malaria control teams in an abandoned native village and in military barracks, in mess halls, on screening and garbage cans, in a bivouac area, in the interior of an airplane, on a man's hair and beard, in a food storage area, on a pond, and in standing water. Larviciding with DDT from an airplane is also shown. Shots include: Laboratory scientists working with DDT; insect larvae; insects swarming.