Beetles, the most diverse group of insects, are often abundant in terrestrial and freshwater ecosystems. Many species are under threat from human changes to natural environments, and some are valuable tools in conservation, because they respond rapidly to changes that occur. Knowledge of these responses, of both abundance and composition of assemblages, enable use of some beetles to monitor environmental changes. Beetles impinge on humanity on many ways: as cultural objects, desirable collectables, major pests and competitors for resources need by people, as beneficial consumers of other pests.