Un scientifique, le Professeur Hellstom, explique la violence et la sauvagerie du monde des insectes. Il filme entre autres les guerres opposant des colonies de fourmis, et les mœurs cannibales des mantes religieuses.
Durant l'été 1976, la ville de Basse-Terre est évacuée car le volcan de la Soufrière est sur le point d'entrer en éruption. Werner Herzog parcourt la ville déserte et décrit la situation.
The film is roughly separated into five sequences. The first sequence features George's narration, where the relationship between the two species is introduced. As Best's narration takes over, the film relates the problem of the "bum" bear and how bears become habituated to human contact and food. A third sequence uses actors to portray a couple camping in Banff. They notice grizzly tracks and subsequently use the Parks' suggested practices when setting up their camp.