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).
Brazilian arboreal mouse found in four other localities in Brazil, near Ubatuba in São Paulo State, including in Pincinguaba State Park, and near Viçosa in Minas Gerais State. It typically lives in Atlantic forest, often among bamboos, and also in modified forest habitats. Little is known about this species and its natural history. Several specimens were caught in pitfall traps sunk in the ground, but it is thought that it is an arboreal rodent, or one that scrambles among the undergrowth, because of the morphology of its feet. Examination of the stomach contents of one individual that was caught showed that it had