Sciuridae

Squirrels belong to the family Sciuridae, which includes small to medium-sized rodents such as tree squirrels, ground squirrels (including chipmunks and prairie dogs), and flying squirrels. They are found in the Americas, Eurasia, and Africa, and were introduced to Australia. The earliest fossilized squirrels date back to the Eocene epoch, and they are most closely related to mountain beavers and dormice.

They typically have slender bodies, bushy tails, and large eyes, with soft and variable fur. Most species have longer hind limbs than forelimbs and either four or five toes on each foot, featuring soft pads and sturdy claws for climbing. Notably, tree squirrels can descend trees headfirst by rotating their ankles 180 degrees to grip the bark.