A squirrel's tail is a multi-purpose tool that functions as a thermostat, balancing rod, and communication device.

The squirrel's tail is a marvel of biological engineering primarily controlled by a process called thermoregulation. Research from the University of California, Berkeley, indicates that squirrels can increase or decrease blood flow to their tails by up to 100 times to manage heat. In cold weather, they restrict blood flow to conserve core warmth, while in heat, they dilate vessels to dump excess thermal energy into the air.Beyond temperature control, the tail is essential for arboreal locomotion. It acts as a dynamic counterweight, shifting the center of gravity to prevent falls during jumps that can span up to 20 feet. This allows squirrels to navigate thin branches and execute sharp turns at high speeds without losing their footing.Communication is another critical function of the tail. A study published in the journal 'Animal Behaviour' highlights how squirrels use 'tail flagging' to warn others of predators. Rapid, jerky movements often signal ground threats like cats, while slower waves may indicate aerial predators like hawks. This complex signaling system is vital for the survival of the colony.