Ground squirrels are rodents of the squirrel family (Sciuridae) that generally live on the ground or in burrows, rather than in trees like the tree squirrels. The term is most often used for the medium-sized ground squirrels, as the larger ones are more commonly known as marmots or prairie dogs, while the smaller and less bushy-tailed ground squirrels tend to be known as chipmunks.
Ground squirrel
20,000-year-old Arctic ground squirrel mummy
California ground squirrel (Otospermophilus beecheyi) in a tree
Watchful "rock chuck" or yellow-bellied marmot (Marmota flaviventris) atop Mount Dana, Yosemite National Park in California
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