Other than pronounced black rings around the eyes, there are no well-defined markings on the face. The dental formula is the same as in the Didelphidae, but the canines, last molars, and first incisors are relatively smaller than those of typical didelphids. The tympanic bullae of Dromiciops are greatly inflated and occupy a relatively large area on the base of the skull. The face is quite short, reflecting the unusually shortened rostrum of the skull. The only naked part of the tail is a narrow strip 25-30 mm long on the underside of the tip.
Females have four mammae in a small but distinct pouch.
It makes small round nests, about 200 mm in diameter, of sticks and the water-repellent leaves of Chusquea , lined with grasses and mosses. Dromiciops is almost entirely nocturnal. In some areas, at least, it hibernates for lengthy periods when cold temperatures prevail and food is scarce. The voice has been recorded as a chirring trill with a slight coughing sound at the end. Both males and females become sexually mature during their second year of life.