What do prison inmates and frogs have in common? Apart from being animals populating this planet, not much, one would say, awaiting the punch line of an apparent joke. The answer though is sobering and thought-provoking at the same time: both prison inmates and frogs (as many other species, e.g., sparrows and crustaceans; see Searcy and Nowicki 2005) engage in aggressive interactions in which they fight over status, territory, and other resources, making their solitary, poor, nasty, brutish, and short lives more pleasurable.