Like many rodents, the Galapagos rice rat is most active after dark (6). After dusk, this species will venture out from its burrow, which is typically situated in the hollow trunk of a cactus or beneath a rock (7). It feeds on a variety of plants, particularly grass seeds, as well as small invertebrates (6).
There is little information available regarding breeding in the Galapagos rice rat. The breeding season is thought to begin after the arrival of the warm season rains between January and May, when food is most abundant (4) (6). During the mating season, the usually nocturnal Galapagos rice rat becomes more active during daylight. Each litter contains between two and five infants, with the number of offspring thought to be dependant on the level of rainfall (4) (8).
The Galapagos hawk (Buteo galapagoensis) and the short-eared owl (Asio flammeus), both frequently prey on the Galapagos rice rat (4).