When you first get a cat, you might spend hours on the internet trying to figure out if some of their behavior is normal. Cats behave so differently from many other pets. Even people who have owned cats for decades can get a feline companion that randomly demonstrates a never been seen before behavior.
Though pet cats tend to jump sideways out of playfulness, the action is a deep-rooted defense mechanism. The original intention of the sideways hop with puffed-out fur and an arched back was to appear larger and fearless in the face of a predator.
This particular leap is common in kittens, but some cats continue to do it as adults. Jumping sideways can indicate aggression or fear, and frequent displays of anger need to be addressed.
The sight of your cat presenting you with its broadest side, a bottle-brush tail, and Batman ears makes you laugh. Then they start hopping towards you in this stance. You think they are playing, but a fluffed-up tail and making themselves look bigger can be associated with fear or anger.

The Origin Of The Sideways Jump
People also use the terms sideways hop and sidewinder when referring to this action. Your cat will start by puffing up its tail and stiffening all four legs. Then it will arch its back and hop towards and away from you, another cat (even if that cat is in the mirror!), or a toy. Their claws are extended, and there is also often a particular and slightly wild gleam in your cat’s eyes as they do this.
Jumping sideways is an instinctive behavior that kittens display. It is based on defensive actions that make the cat look bigger and, therefore, more intimidating, and it also brings more paws and claws into the space between the cat and the potential threat.
Cats Jumping Sideways Typically Indicates Playfulness
Despite its origins as a defensive behavior, when your cat jumps sideways, it is almost always a display of playfulness, especially if your cat is still a kitten. But how can you tell it is playfulness? Cats actually communicate vividly through their body language. There are subtleties, but for the most part, you can clearly read your cat.
When they playfully jump sideways at you, your cat will be showing signs of being non-aggressive. Your cat’s tail will likely be down but not tucked against their body, which would indicate fear. Their ears will be drawn back but not pinned against their head, which would suggest aggression. Your cat will also quickly return to a neutral or relaxed posture.
However, probably the most definitive sign that your cat is only playing when they hold this posture is the lack of vocalization (hissing, spitting, and growling) and teeth-showing.

Is It Normal For Adult Cats To Jump Sideways?
The sideways hop is most often seen in kittens from about five or six weeks of age. At this age, kittens are confident enough on their feet to engage in more active and coordinated play. Even though they have more control of their bodies, young kittens will still often sideways jump themselves right off the couch or bed.
Although sideways hopping is not uncommon or abnormal in an adult cat, they are less likely to engage in this play than kittens, and if they do, they will not jump sideways as often.
How Should You Respond To The Sideways Hop?
According to Animal Planet, the correct and proper response to the sideways hop is to get down onto all fours and sideways hop back at your cat; this is what another cat would do. Maybe they are teasing their readers?
You might be tempted to adapt this response to involve only your hand, running your fingers over the floor, bed, or couch. However, people are actually discouraged from playing with their cats with empty hands.
If they start to see your hands as toys, it can lead to very unpleasant consequences. Remember, a kitten’s teeth and claws can hurt, and they grow bigger and stronger every day!
Instead, you should grab one of their favorite toys and wriggle it for them to jump at and pounce on. This could be a fake mouse, a ball, a piece of string, a ribbon tied to a stick, or even just a scrap of paper.
Do Cats Ever Jump Sideways At You When They Are Angry Or Scared?
Even though the sideways hop is most often a playful action, cats can also do it when they are scared or angry. In this case, they are using the behavior to make themselves look intimidating.
You can differentiate this from playful behavior by looking at the other signs. Ears pinned right down against a cat’s head, bared teeth, and a tucked or upright, bottle-brushed tail are indicators of distress.
If your cat hisses, spits, or growls, it will also be a sign that negative emotions are in play.
If another cat is involved, you can use their response to measure the situation. If they run away scared, cower, cry, or growl back, then the behavior has gone past the point of being playful, and you should intervene.
Some cats will use this as a bullying tactic for smaller or less dominant cats.
A scared cat will hop towards you and then retreat, preferring to hide than attack. An aggressive or fearfully aggressive cat might jump close enough to smack you or another cat with their extended claws.
You will need to put a stop to this behavior, but don’t punish them. Cats do not respond well to punishment, and if aggression is based on fear, this will only make the situation worse.

What Causes Aggression In Cats
The first thing to do is to rule out a medical condition. There are some disorders that can lead to excessive aggression in cats. Additionally, cats can respond to pain with anger. Your vet may recommend neutering or spaying your cat if you have not already had them sterilized. The hormones in intact cats can trigger aggressive behavior.
If there is no medical explanation, you need to try to identify what is triggering the anger or fear. It is unlikely to be the unelicited response of an innately mean cat. Cats are aggressive due to territorialism, maternal instincts, overstimulation, and fear.
With territorial aggression, your cat may jump sideways towards you or another cat when their territory is trespassed upon. A mother cat can display this behavior in an effort to defend and protect her kittens.
Sideways jumping can start playfully and then cross over to aggression when a cat becomes overstimulated.
Fear aggression is probably the most common cause. It can be the result of genetic predisposition, but socialization has a big impact on a cat’s confidence and ability to regulate its emotions.
Once you know what the cause of the aggression is, you can speak to your veterinarian or an animal behaviorist as to how to regulate your cat’s response to these triggering situations.
Conclusion
When cats turn to the side, arch their backs, bottle-brush their tails, and start to jump towards you, it is undoubtedly a very comical sight. But the sparkle in their eyes may cause you a moment of concern. Then they pull up short of reaching you and hop away again.
Thankfully, this behavior is more likely to be the playful expression of instinctive behavior. It is most often displayed by kittens, who will jump so vigorously that they fall over or hop straight off the couch or bed on which they were playing. However, adult cats can also still engage in sideways jumping, but they are decidedly more coordinated.
Occasionally, this behavior is accompanied by hissing, spitting, growling, and swatting. This is an aggressive response that needs to be addressed in the correct manner, which will depend on the cause.