There are 100 species of rice rat, all looking much like the Baja California species and leading similar lives. They feed mostly on green vegetation, such as reeds and sedges, but also eat fish and invertebrates. They can become serious pests in rice fields and can cause severe damage to plants. They weave grassy nests on reed platforms above water level or, in drier habitats, excavate burrows in which they breed throughout the year, producing 7 young in each litter.