A rodent is a mammal that belongs to the order Rodentia, characterized by a single pair of continuously growing incisors in each of the upper and lower jaws
. Rodents are the largest group of mammals, constituting almost half of the class Mammalia's approximately 4,660 species
. They are indigenous to every land area except Antarctica, New Zealand, and a few Arctic and other oceanic islands
. Some well-known rodents include mice, rats, squirrels, prairie dogs, porcupines, beavers, guinea pigs, and hamsters
. Rodents play a significant role in human populations, both positively and negatively. They can damage crops, contaminate stored food, and cause structural damage to buildings, but they also serve as important food sources for many predators and contribute to ecosystems
