Rodent on every continent except Antarctica. They are the only terrestrial placental mammals to have colonized Australia and New Guinea without human intervention. Humans have also allowed the animals to spread to many remote oceanic islands (e.g., the Polynesian rat). Rodents have adapted to almost every terrestrial habitat, from cold tundra (where they can live under snow) to hot deserts. Some species such as tree squirrels and New World porcupines are arboreal, while some, such as gophers, tuco-tucos, and mole rats, live almost completely underground, where they build complex burrow systems. Others dwell on the surface of the ground, but may
Asháninka arboreal chinchilla rat and lips, large claws, and a line of white fur running down its head. It is in length, with a tail of . It weighs . Ashaninka arboreal chinchilla rats live in dwarf forest and are hunted by long-tailed weasels. When described, it was placed in the family Abrocomidae, but was considered different enough from existing species for the creation of the genus "Cuscomys". Since then, the Machu Picchu arboreal chinchilla rat ("Cuscomys oblativus"), a species of chinchilla rats originally placed in the genus "Abrocoma", has been shown to be a member of "Cuscomys". Although it was considered extinct by