 At Papallacta, "Thomasomys ucucha" was collected in a variety of habitats at altitude, including "páramo" (high-mountain grassland with shrubs and forest patches) and subalpine rainforest.Most were taken in runways (paths through vegetation made by animals) and a few alongside small streams or on a low tree.At Guandera Biological Reserve in Carchi, the species has been found at a slightly lower elevation, .