Solitary life-styles are restricted to species living in arid grasslands and deserts. Having very acute senses, rodents communicate by sight, sound and smell. They make considerable use of vocalizations, some of which are above the human hearing range. Scent marking, usually by urination, is very common. Rodents are the most successful mammals in terms of geographical distribution.
Many species are pests that feed on cultivated crops and other human foods.
Conversely, only a few species have been deliberately bred for food. Guinea pigs are still a source of protein in the Andes, as they were for the ancient Incas. Capybara are being raised in Venezuela for market and the wild capybara have long been a choice food for natives of the South American tropical forests. Chinese peasants eat hamsters. Several species have had great economic influence because of their fur.