Why Do Cats Arch Their Backs?

Cats are modern marvels in the flexibility department, contorting into pretzels while napping, flipping over mid-fall to land on all fours (righting reflex), and shimmying beneath the sofa with no trouble. But this flexibility takes on an unusual twist when Fluffy’s back shoots sky-high in an adorably fuzzy arch formation. The curiosity gets the best of you: Why do cats arch their backs?

Cats arch their backs to express fear, often paired with a puffed-out tail and hissing in the classic scaredy-cat position. But felines also arch their backs while playing (mimicking a predator encounter), stretching after a nap to return normal blood flow, and while content mid-petting session.

This back-arching habit in cats sends an emotional message that you struggle to decipher. The only way to know for sure is to observe what happens before and during this outstretched position takes hold. To learn about why cats arch their backs, read on!

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The Classic Back Arch in Felines

The classic feline back arch looks mildly painful to the naked eye. Sometimes dubbed the “Halloween pose” or “scaredy-cat position,” this towering mid-back is possible, thanks to a cat’s ultra-flexible spinal anatomy.

Cats have 30 vertebrae creating the spinal column, and, though it resembles that of other mammalian species (including humans), it takes the term “flexibility” to new extremes. On top of very flexible tendons and ligaments in the back, there’s an elastic disk wedged between each spinal bone that provides superior cushioning and some 180° rotation — twice that of humans.

This unique anatomical structure is the same reason cats can sprint up to 30 mph, leap 5-6 feet (1.52-1.83 meters) high, sleep with their front and rear legs facing opposite directions, and spin 180° mid-air.

Why Cats Arch Their Backs

Unless a cat is purring, hissing, or swatting, it can be challenging to decipher what a cat feels or is trying to express. The trick to understanding this obscure back-arching is taking note of what happens before and during the arch. Generally, Fluffy might arch her back for one of four reasons:

To Stretch/Relax

If your first instinct after your alarm clock jolts you awake is reaching your arms above your head to stretch, you and your kitty aren’t so different. The traditional feline back arch trails a deep slumber or long sunbathing session where a cat is completely inactive.

This satisfying and relaxing stretch helps release tension in a cat’s back and shoulders, known to become mildly stiff (or tense) when snoozing for hours on end. The back arch also helps a cat:

Reverse low blood pressure
Increase blood flow to the muscles (warm them up for the next pounce)
Release lactic acid and carbon dioxide build-up (loosen up the muscles)
Encourage endorphin release (the “feel-good” hormone)

Your cat’s first instinct post-nap might be to arch her back, sometimes so tensely that she shakes or emits an adorable squeak. Other common stretching positions include extending their legs back while walking slowly or the classic bow position (just as dogs do).

Since cats sleep upwards of 20 hours a day, this arched back is likely a daily scene in your home.

To Express Fear

A startled cat’s first instinct is to enter “defense mode” when face-to-face with a predator (ex: raccoons and eagles), when encountering a stranger, or when a loud noise spooks them.

When a cat is in fear for its life, it’ll contort its body to appear bigger and more intimidating. This fear response is the same reason cats puff-out their tails (piloerection), arch their backs tightly, walk sideways (more than doubling their size), growl or hiss, bare their teeth, and freeze.

You’ll know it’s fright triggering that arch if it always follows a sudden fear trigger, like turning on a loud vacuum cleaner or when a territorial cat waltzes near.

How to Soothe a Fearful or Anxious Cat

Your first instinct to help your frightened cat might be to pick her up or tickle her forehead, but these innocent responses might trigger even more anxiety. If your cat is scared, remove the stimuli (ex: turn off the vacuum or shut the door), give her room to flee, and remain calm. Don’t scold your cat if she hisses or swats, and allow her to lead the way.

Not all felines are social butterflies willing to greet you at the door and loop their tails around strange house guests. The video below explains how to help a naturally shy or scared cat:

To Show Contentedness

On the opposite end of the spectrum, a cat’s arched back can also signal pleasure and happiness. That back might raise sky-high as your kitty weaves between your legs or as you’re offering massage-like back scratches. The back arch takes on two new translations:

That’s the spot right there!: If your cat raises her back even closer toward your hand mid-petting session, she’s begging for more scratches in her favorite spot and helping you reach it better.
You’re mine!: Along with a raised back, some kitties will lift their butts high into the air (affectionately coined “elevator butt”). In turn, those pheromone-releasing anal glands get closer to your skin and help Fluffy spread her scent with little effort.

A happy cat won’t only offer a distinct, tight back arch. That content fur ball might also purr, blink slowly (or even shut her eyes), meow affectionately, or dilate her pupils. The best way to strengthen your bond with Fluffy in these scenarios is to lend a helping hand and scratch!

It’s not every day your kitty begs you for attention.

Where Do Cats Like To Be Petted?

Most cats can’t get enough of those soothing back scratches and long relaxing strokes, but that’s not the only place Fluffy enjoys gentle massages. Research shows that cats also enjoy petting:

On the chin
Along the neck
At the base of the ears
On the forehead

Watch how your cat responds to different petting experiments. If her skin ripples or twitches, her tail swishes, or she looks directly toward your hand, Fluffy is letting you know that it’s too much.

To Play/Romp Around

Young kittens have a quite dramatic playing style, mimicking adult cat instincts a bit more clumsily. In particular, playful kitties are notorious for staging mock fights with both predator and prey, honing their offensive and defensive skill sets without fleeing a seething coyote in the wild.

During these mini ambush sessions, a kitten will arch her back to look bigger, approach with a humorous sideways prance, and then pounce playfully.

The key differences here are that these play sessions don’t include piloerection, a puffed tail, spitting, hissing, or growling. Fluffy might choose her favorite mouse toy or a littermate as her “prime target,” but any biting is gentle mouthing, and both kitties take turns being the aggressor.

If your kitten arches her back or crouches down as you walk past, expect a friendly ambush!

Conclusion

Like many odd feline behaviors, cats rarely arch their backs for no reason. If your cat is arching her back with no obvious explanation, look a little closer. Fluffy is likely saying:

After waking up: “Wow, that was a relaxing nap!”
When spooked: “Don’t come any closer or else!”
During a petting session: “More back scratches, please!”
While playing: “Watch out; I’m going to get you!”

Don’t forget to look for any unusual changes in your kitty’s behaviors over time. For example, if your cat responds to back scratches with swats instead of purrs, consider a vet appointment.

Sources

Pam Turner

Pam is a self-confessed cat lover and has experience of working with cats and owning cats for as long as she can remember. This website is where she gets to share her knowledge and interact with other cat lovers.