Squirrels, with their quick movements and bushy tails, are a common sight. Their frequent body or tail twitching often prompts curiosity. This behavior is a natural aspect of squirrel biology, hinting at various functions from internal processes to external communications.
Involuntary Body Processes
Squirrel twitching can stem from internal physiological functions. These small mammals maintain a high metabolic rate, influencing many bodily processes. Their breathing rate is rapid, often 100 to 125 breaths per minute, significantly faster than humans. This fast respiration can result in subtle, involuntary body twitches, especially when a squirrel is at rest.
Muscle activity also contributes to twitching. Squirrels experience muscle twitches even during stillness or sleep. These twitches can be a precursor to movement or an involuntary response of their active musculature. The need for constant energy to fuel movements and maintain internal temperature contributes to their high activity and minor movements.
Vigilance and Awareness
As prey animals, squirrels are constantly alert. Their twitching behavior is a component of their vigilance and environmental awareness. This includes scanning for threats like hawks, foxes, or snakes. Twitching, especially of the head, ears, and body, allows them to quickly detect subtle environmental changes or movements.
Their sharp senses of sight and hearing are attuned to their surroundings. Squirrels have wide-angle vision and good depth perception, aiding their ability to assess distances for leaping and navigating. The slightest sound or visual stimulus can trigger a twitch as they process information and evaluate dangers. This readiness, manifested through twitching, enables instantaneous reaction, whether fleeing or preparing a defensive maneuver.
Communication and Warning Signals
Beyond involuntary movements and vigilance, squirrel tail twitching serves as communication. The rapid flicking of their bushy tails, known as tail flagging, signals other squirrels. This is an alarm signal, alerting nearby individuals to a predator or perceived threat. For instance, a squirrel might vigorously wag its tail to indicate it has spotted a feral cat, warning others of danger.
Tail flagging also deters predators. By flicking its tail, a squirrel signals to a predator that it has been seen, potentially discouraging pursuit by removing the element of surprise. California ground squirrels can even heat their tails while flagging during encounters with snakes like rattlesnakes, which is believed to confuse the snake’s heat-sensing abilities. Tail twitching can also convey a squirrel’s emotional state, including agitation, frustration, or excitement. Squirrels increase tail flicking when frustrated by an inability to access food.