What Your Cat's Tail Can Tell You

Cats communicate in a variety of ways. Their purrs can have different meanings, but they also use a species-specific cat tail language to convey fear, excitement, contentment, curiosity, and aggression. The position of their furry rear appendages usually coincides with certain ear placements: upward-turned when alert or happy, back and flat when irritated or frightened. Together, these body language cues are a good barometer of a feline's mood.

Here are 12 distinctive cat tail positions and how to decode them.

Cat Tail Curved Like a Question Mark

An erect tail with a curve at the tip that resembles a shepherd's crook or a question mark typically indicates friendliness or playfulness, but can also mean the cat is inquisitive (fitting for this particular punctuation mark) or unsure. According to Beverly Hills Veterinary Associates, Inc., the defining crook at the end could either be an expression of wariness or a cue that the cat wants to spend time with you — deciding which depends on whether it seems interactive or standoffish.

Cat Tail Straight in the Air

When a cat holds its tail straight up, it's almost definitely happy, says the Animal Medical Center, a large nonprofit animal hospital in New York. An upright, unbending tail can be an expression of confidence, excitement, or contentment. You'll most often see this when you walk through the door after work or when a kitten greets its mother. When cats that are unfamiliar with each other display this tail position, it means they want to interact amicably, one study said.

Tail Held Low

While some cats may allow their tails to hang down lazily when they're relaxed, a tail that is held low to the ground (lower than horizontal with its body but still angled, not quite tucked between its legs) is more often than not a sign of defensiveness, fear, or anxiety. According to Beverly Hills Veterinary Associates, this could potentially lead to aggression. Note whether this tail position coincides with an arched back, flattened ears, or a swishing of the tail — this is known as a distance-increasing posture and is meant to warn others to stay away.

Certain breeds — including Persians and Scottish folds — tend to carry their tails low even when they're feeling playful.

Cat Tail Swishing From Side to Side

When a cat moves its entire tail (as opposed to the tip only) slowly from side to side, it must be zeroed in on a particular object, such as an insect or a toy. This motion is more calculated and ominous than a dog's excited tail wagging, as it indicates that the cat is enticed by something and probably gearing up to pounce. According to PetMD, this side-to-side motion is typically coupled with intense focus, stalking, and pouncing, all healthy predatory behaviors.

Thumping Tail

A tail that whips back and forth with more ferocity than a graceful swishing, or one that thumps loudly against the floor indicates that a cat is agitated or fearful, says professor Bonnie V. Beaver in the book, "Feline Behavior." This action differs from more gentle wagging in that it's not inquisitive or playful and will likely lead to aggressive behavior. A thumping or thrashing tail is often a sign of irritation.

Puffy Cat Tail

You can tell when a cat is afraid or feels threatened by the way its hair stands on end. One distance-increasing posture is the classic Halloween black cat silhouette: the one in which the cat's spine is arched and its hair is erect along its back and down its tail. Cats do this to stave off potential threats as they "lack the confidence to stare down and charge others," the American Society for the Prevention of Cruelty to Animals says.

Tail Tucked Under

When a cat's tail is tucked tightly beneath its body, between its legs, it's likely a sign of fear, uncertainty, or submission. Something in the cat's environment is making it uneasy. The ASPCA says that when a cat does this with its ears sideways or back, pupils dilated, and body turned away or sunken close to the floor, it indicates nervousness.

If its ears are flattened, its body crouched, whiskers back, and back legs outstretched, it's likely a sign of defensiveness. In this case, the cat may meow, growl, hiss, or spit.

Tail Wrapped Around You or Another Animal

If your kitty wraps its tail around you or another pet in your household, this small display of affection is akin to placing an arm around a loved one — it indicates companionship. According to the ASPCA, this is a distance-reduction behavior, meant to "encourage approach and social interaction" and to "telegraph to others that the cat means no harm." You may expect to hear purring when this happens, especially if you decide to go in for a pet.

Tail Wrapped Around Its Own Body

There is a difference between a cat that holds its tail against its body when it's relaxed or sleeping, indicating contentment, and one that holds it tightly to its body while crouching in defense. This may coincide with a hiss or other threatening sound, or flattened and pinned-back ears. Pupils may dilate in a standoff situation, allowing for wider peripheral vision in anticipation of an imminent attack, the nonprofit Cats International says. A cat may also assume this position if it's cold, as the fur on its tail helps to keep its toes warm.

Quivering Tail

You may notice a cat's tail quivering when it's marking its territory. Urine marking is common among cats that have not been spayed or neutered. The cat will back up to a vertical surface, lift its tail high and spray the surface with urine, with its tail quivering all the while. Cats mark their territory as a way to cope with stress, perhaps caused by a change in environment or the addition of a new pet.

Tail Twitching at the End

A tail that twitches at the tip could mean a couple different things, depending on the context. This often happens when a cat is actively playing with a toy or hunting and in a crouched position. In both of these scenarios, considering play is sort of an indoor cat's version of hunting, tail twitching is a sign of concentration and curiosity. Alternatively, a twitching tail while the cat is seated and its ears are back can indicate irritation, according to PAWS Chicago animal shelter. This can result in growling, biting, or scratching.

Shaking or Vibrating Tail

When cats hold their tails straight up in the air and shake them rapidly at the base — an act similar to quivering, but not accompanied by urine spraying — this typically means they're excited to see you, says Phoenix Veterinary Center's Dr. Evan Ware in a post on Wedgewood Pharmacy's blog. Many cat owners report that their pets do this before being fed or receiving treats. A cat whose tail is upright and vibrating is usually friendly and approachable.