Brazilian gracile opossum habitats than more purely arboreal animals. It has also been found in artificial plantations. There are no recognised subspecies. Brazilian gracile opossums are arboreal and nocturnal, spending the day nesting in tree hollows. They are solitary animals, with each individual inhabiting a home range of anything from , depending on habitat. Males tend to have larger home ranges than females, presumably because, being larger, they require more food. The species is insectivorous, and is an opportunistic forager, not specialising in any particular kind of insect. Individuals have also been reported to eat some spiders, snails, and even fruit (including passionfruit).
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