The underparts are white, creamy, or pale brownish or gray. Like Uromys, these rodents are easily recognized by their almost naked, filelike tail. The scales of the tail form somewhat of a mosaic pattern, which differs strikingly from the evenly ringed arrangement seen on the tails of the typical rats. The feet are broad and have well-developed pads. From Uromys, Melomys is distinguished externally by its smaller size.
Most species are basically terrestrial but capable of climbing.
Nests are also located among roots, in hollow timber, and under rock ledges. Aboveground nests, made of grass or leaves, are spherical and usually 125-200 mm in diameter. The diet of Melomys is thought to consist of fruits, berries, and other vegetable matter. In an investigation of M. burtoni in the Northern Territory, Begg et al. Breeding occurred throughout the year.