The order Rodentia is the largest group of mammals, comprising over half of all present-day species (> 2,000). They are herbivores or omnivores and live in all environments, including the driest. They have a wide variety of lifestyles, ranging from arboreal to aquatic and even gliding. They are mainly characterised by the presence of a single pair of incisors in each jaw. These gnawing teeth grow continuously throughout the animal’s life. They can walk, hold food, suspend themselves and build their nests using their forelimbs.
Rodents are a key group in the balance of ecosystems, both in terms of the biomass they constitute and their ecological importance as primary consumers and main prey for many carnivores. Most rodents have an important and complex social structure and a good learning capacity.