Squirrels

Squirrels are members of the family that includes small or medium-size rodents. It includes tree squirrels, ground squirrels (including chipmunks and prairie dogs, among others), and flying squirrels. These adorable creatures are native to the Americas, Eurasia, and Africa, and were introduced by humans to Australia. They live in almost every habitat, from tropical rainforest to semiarid desert, avoiding only the high polar regions and the driest of deserts. As their large eyes indicate, squirrels have an excellent sense of vision, which is especially important for the tree-dwelling species. Many also have a good sense of touch, with vibrissae on their limbs as well as their heads. In general, the ground-dwelling squirrel species are social, often living in well-developed colonies, while the tree-dwelling species are more solitary. Ground squirrels and tree squirrels are usually either diurnal or crepuscular, while the flying squirrels tend to be nocturnal. They are predominantly herbivorous, but many will eat insects and even small vertebrates. Squirrels reproduce once or twice a year and give birth to altricial young. They are born naked, toothless, and blind. In most species of squirrel, the female alone looks after the young, which are weaned at six to ten weeks and start to breed by the end of their first year.