Calomys is a genus of rodents commonly known as the "bristle mice." They are primarily found in South America, particularly in countries like Argentina, Brazil, and Paraguay. These small mammals are characterized by their soft fur and long tails, which help them navigate their habitats, typically grasslands and forests. These rodents are known for their adaptability and can thrive in various environments. Calomys species are primarily nocturnal and feed on seeds, fruits, and insects. They play a significant role in their ecosystems as both prey for larger animals and as seed dispersers, contributing to the health of their habitats.