Rodents

Rodents make up 40% of all mammalian life on Earth. They are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws which must be kept short by gnawing. Common rodents include mice, rats, squirrels, porcupines, beavers, guinea pigs, and hamsters. Rodents use their sharp incisors to gnaw wood, break into food, and bite predators. Most rodents eat seeds or plants, though some have more varied diets. Some species have historically been pests, eating seeds stored by people and spreading disease.