Rats are various medium-sized, long-tailed rodents. Species of rats are found throughout the order Rodentia, but stereotypical rats are found in the genus Rattus. Other rat genera include Neotoma, Bandicota and Dipodomys.
Rat
A rat in a suburb of Vancouver
Skeleton of a black rat (Rattus rattus) on display at the Museum of Osteology.
A closeup of a rat tail
Rodents are mammals of the order Rodentia, which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are native to all major land masses except for New Zealand, Antarctica, and several oceanic islands, though they have subsequently been introduced to most of these land masses by human activity.
Image: Capybara (Hydrochoerus hydrochaeris)
Image: Springharelg
Image: Goldmantelziesel
Image: American Beaver