examples of rodents 
Amphibious rodent found in Eurasia and North America prized for its fur; it uses branches to build lodges and dams in streams.
Rodent originating in South America, sometimes domesticated but mainly used in laboratory experiments.
Omnivorous rodent characterized by its intelligence; it can transmit certain viruses and bacteria to humans. Some species are domesticated.
Rodent of the Northern hemisphere prized for its fur; it hibernates six months a year and emits a high-pitched whistle when in danger.
Rodent found on land and in trees in warm and temperate regions; its body is covered with long sharp quills, which it raises to defend itself.