Entomology, the study of insects. Scientists specializing in this field are called entomologists. They are chiefly interested in how each kind of insect either harms or benefits humans. They study the origin, development, structure, habits, and distribution of insects. Entomologists work in universities, for government agencies, and in private industry. They have helped chemists develop insecticides, farmers control crop and livestock pests, and physicians conquer diseases spread by insects.