The torpor-prone monito del monte covers its nest with moss. This small South American marsupial uses moss as an outer covering that helps camouflage the nest while also providing insulation and protection from wet, changeable weather.
Monitos del monte build rounded nests in places such as tree cavities, fallen logs, dense vegetation, and bamboo understory. The nest structure can include waterproof leaves, while softer plant material such as moss helps create a sheltered interior. The animals may share nests, especially when raising young.
The species is unusual among South American mammals because it belongs to Microbiotheria, an ancient marsupial lineage with closer evolutionary ties to Australasian marsupials than to most living American marsupials. It is also strongly associated with temperate forests of Chile and Argentina and helps disperse the seeds of the parasitic plant Tristerix corymbosus.
A common mix-up is to assume that clay or feathers are involved because many animals reinforce or line nests with those materials. For the monito del monte, moss is the distinctive camouflage and weatherproofing material highlighted in natural-history accounts.