The harder enamel is restricted to the front of the tooth so that as softer dentine is worn away, a sharp chisel-like cutting edge is maintained. There are eight species described in four genera. Much like the heteromyids, these pedetids are saltatorial, with large hind feet and elongate tail. Their distribution is virtually world wide, except for North Africa, Australia, southern South America, and the marine islands. Some cricetids, such as the muskrat, are aquatic, but most live on dry land.
Some species are fossorial, others are saltatorial.
They are distributed throughout the world except the Malay Penninsula and adjacent islands. These rodents are dispersed throughout western North America but extending through Central America to parts of Columbia. These mammals are highly specialized for fossorial life, and have developed prominent cheek pouches for food storage, giving them their common name. Dormice resemble squirrels in their bushy tail, large eyes, and general habits. These are not to be confused with the spiny dormice, Family Platacathomyidae, below.