Squirrels are social animals. Although adults live alone in nests called dreys throughout the warmer summer months, they co-exist quite happily. Squirrels communicate in a variety of ways, including a range of calls. However, their main method of communication is their tails, which they bush out, shake and twitch to signal their emotional state and warn each other of danger.
"Tell tail" signals
To us, it’s a twitching tail, to another squirrel it’s as plain as writing. Squirrels twitch their tails to attract a mate, to signal danger and to call other squirrels to a meal. Squirrels have exceptional sight, with eyes positioned so that they can even see behind their own heads, so visual signals are an effective communication method that can be subtle. When lesser sighted predators are around, a twitching tail is less of a giveaway than a vocal signal.
Not that squirrels are cowardly creatures. In fact, they can be fairly aggressive in self-defense, and their tails come in handy here too. The tail often makes up half of the squirrel’s body length. Covered in thick bushy fur, with few bones and arteries, that tail makes an excellent decoy. So good that a captured squirrel’s tail may break off, giving the squirrel the opportunity to escape relatively unscathed.
Squirrels will shake their tails at predators to warn them off if they think they have a fighting chance. In fact, squirrels have obtained a reputation as bossy and defiant, because they will bravely take on a fairly large predator, throwing soil at it with their front paws, biting or swiping at the predator, with a bite that can leave a nasty infection.
Squirrels have evolved alongside one of their main predators, the rattlesnake, in a prolonged battle of evolutionary wits. As the snake developed venom, the squirrel developed an antitoxin. They also use their tails to discourage snake attacks in a remarkable way.
Although scientists at the University of California who studied the behavior are not sure why it works, or even quite how the squirrel manages to pull off the feat, a squirrel confronting a predatory rattler is able to heat its tail by several degrees. Waving the heated appendage either confuses the snake or convinces it the squirrel is a larger animal, since it has poor eyesight and is sensitive to infrared heat signals. The poor rattler then slinks off to find an easier meal.
Interestingly, the squirrels somehow know which snakes have heat sensing pit organs, because they don’t heat their tails when gopher snakes, which don’t have them, attack. They also wave their tails at an approaching snake more at night time than during the day, so it’s not just a visual signal. The snakes aren’t quite as bright though. They will go on the defensive and slither away when confronted by a stuffed squired with its tail heated and mechanically twitched as if they were facing a real squirrel.