The rodent is a contains Rodentia and Lagomorpha (rabbit, hare and pika) evolution branch. Rodents, English rodent, the term derives from the Latin for "bite". Of rodents.Rodents and other mammals is different, they have two pairs of teeth -- a pair of front teeth and a pair of lower incisors. The two of them with life in front, bite, teeth becomes like a chisel tip in general. Rodents have no canines, many species of rodent incisors and molars with a long soft hairy, the sawdust and other inedible things such as barrier between wall of the mouth and teeth, preventing them from entering the mouth. A lot of rodents with cheek pouches long, used for temporary storage of food.Most rodents living in caves, there is also a part of living in the trees and the water. Almost all of the rodents are herbivores, but there are exceptions, such as the squirrel is both a herbivorous carnivorous rodent.