A rodent is a member of the taxonomic order Rodentia. Rodents are known for their fur (typically brown or gray), tails, and ever-growing teeth. Rodents are native to most islands and every ... Learn about rodents, a diverse group of small to medium-sized mammals with ever-growing incisors. Find out their classification, distribution, adaptations, and examples of rodents like mice, rats, squirrels, beavers, and more. What Are Rodents? Rodents are the most diversified mammalian order, representing about 40% of all mammals. Rodents, mammals of the order Rodentia, represent about 40% of all mammalian species. They are found across the world in all continents with the exception of Antarctica where they inhabit a wide variety of habitats. They can be arboreal, semi-aquatic or fossorial in nature. They are characterized by a pair of unremittingly growing incisors, both in the upper and lower jaws. Here we ... Rodents are members of the order Rodentia, which is the largest order of mammals. Rodents are mostly distinguished by their teeth—the word "rodent" comes from the Latin word rodere, meaning "to gnaw." There are about 1,500 species of rodents including mice, rats, squirrels, and beavers (Nowak, 1983; UCMP, 2007). They are found on all continents except Antarctica and in almost all land habitats, from tropical forests to deserts to mountains to tundras. Rodents and bats are the only orders ...