A rodent is a mammal such as a mouse, rat, squirrel, hamster, chipmunk or beaver that gnaws or nibbles its food. The name comes from the Latin verb rodere, meaning to gnaw.

This is the skull of a small rodent although we are not certain which animal it is.You can tell it is a rodent by the very large incisor teeth at the front of the mouth. These never stop growing - they can grow up to 12 cm per year. They are used to gnaw at hard substances and this action of gnawing stops them growing too long.  Squirrels can use these teeth to break open nuts. The flatter molars at the back are for grinding the food; this animal has four.

Animals that eat mainly grass, called herbivores, do not have incisors. They only have the molar teeth. Animals that eat meat, called carnivores, have sharp molars so that they can tear into their food.