This paper explores the reasons for industries converging upon poor strategies. The phenomenon is likened to the periodic mass suicide of the lemmus lemmus (the Norwegian lemming). It gives historic examples of the phenomenon, and evidence of its occurring within a simulated business environment. A literature review shows how it can be explained using theories from economics, psychology and competitive analogies used in business. An inputs-process-outputs model provides a theoretical framework for Lemmus Lemmus strategies and is used to derive hypotheses.