The color of the tail ranges from dark, dull, grayish brown to blackish above and is slightly lighter below, but it may be dull yellowish in some species. The tail is naked except for a few scattered hairs, and the large ears are sparsely haired. Ototylomys closely resembles Tylomys but is smaller and has a somewhat shorter tail. This rat occurs in a wide variety of habitats but prefers tropical forest with rocks or rocky ledges. Its altitudinal range is sea level to about 2,000 meters.
Available information indicates that breeding occurs throughout the year in the wild.
A postpartum estrus was observed for all littering females. The young weighed about 10 grams at birth, and most opened their eyes at 6 days. The earliest recorded mating for a female occurred at 29 days.