Cat communication

Cats will bite out of contentedness, playfulness or aggression. When a cat is content, the cat may sometimes make a weak and harmless bite many owners refer to as a 'nip'. Nipping appears to be akin to human kissing, and as such will be accompanied by other gestures of affection which (depending on the cat) include purring, vertical tail, forward whiskers, rubbing of the face on nearby objects, arching of the back when petted, etc.

This YouTube video shows a cat stalking as play.A common misunderstanding is that all "affectionate" biting is nipping. When a cat becomes irritated or tired of being petted (ie. being rubbed the wrong way, being irritated by static electricity, being sore, wanting to sleep, or just being cranky), the cat may cease to nip and start to bite. The crucial difference is that the cat will bite harder than a nip but will rarely be painful, and will be displaying other signs of irritation at being petted (ie. purring stopped, tail no longer vertical, whiskers and ears pointed backwards, paw swiping at the petting hand before or immediately after the bite).

This is not a sign of outward aggression, just simply a terse request that the cat's human companion should immediately stop some action which the cat has ceased to enjoy.Playful clawing and biting often happens when teasing a cat (especially a kitten) with fingers or a toy. The cat will lunge at the toy (or the fingers manipulating the toy) and possibly claw or bite. The clawing and biting is sometimes painful but rarely causes injury - either the cat becomes overcome with excitement or, especially in the case of kittens, is still learning it can injure its friends. The cat's intent is still one of affection and playfulness (forward-pointed whiskers, purring, other obvious appreciation of the game). It is recommended that the human emit a high-pitched noise suggesting pain and a firm "NO!", followed by ignoring the cat for approximately ten minutes.Aggressive biting is obviously designed to cause injury. Domesticated cats rarely bite with injurious intentions. However, should the cat be rabid or feel that a human (even a friend) might present a mortal danger for some reason, the cat may respond with aggression. An injured cat, may bite defensively when approached. Female cats, when nursing new kittens, can also be aggressive when approached before the cat has introduced her kittens herself. 

Purring 

A purr is a sound made by some species of felines and is a part of cat communication. It varies in detail from cat to cat (e.g., loudness, tone, etc.), and from species to species, but can be characterized as a sort of tonal buzzing. All domestic cats purr in a frequency range of 22.4 to 30.2 hertz. Some cats purr so strongly that their entire bodies vibrate; conversely, other cats may purr so quietly that the only indication is a vibration when touching the cat's throat. In addition, some are able to meow or hiss without interrupting the purring sound. 

Other noises 

Most cats growl or hiss when angered or in danger, which serves to warn the offending party. If the warning is not heeded, a more or less serious attack may follow. Some may engage in nipping behavior or batting with their paws, either with claws extended or retracted. With cats who are improperly socialised and do not know their own strength, this can result in inadvertent damage to human skin. Like any injury, cat scratches can become infected, and in extreme cases can result in cat scratch fever.Cats are also known to make chirping or chattering noises when observing prey, or as a means of expressing interest in an object to nearby humans. When directed at out-of-reach prey, it is unknown whether this is a threatening sound, an expression of frustration, or an attempt to replicate a bird-call (or replicate the call of a bird's prey, for example a cicada).  Whereas this conduct was originally viewed as the feline equivalent of song, recent animal behaviorists have come to believe this noise is a "rehearsal behavior" in which it anticipates or practices the killing of prey, because the sound usually accompanies a biting movement similar to the one they use to kill their prey (the "killing bite" which saws through the victim's neck vertebrae).A type of chirrup, the chudder, is used as a greeting. Tigers also use this sound. Some cats may also grunt when given attention. The grunt appears to always be modulated with a purr, making it a kind of closed-mouth meow of affection. Cats in close contact with humans use vocalization more frequently than cats who live in the wild. Adult cats in the wild rarely vocalize; they use mostly body language and scent to communicate. 

Body language 

Cats will twitch the tips of their tails when hunting or angry, while larger twitching indicates displeasure. They may also twitch their tails when playing. A tail held high is a sign of happiness, or can be used as a greeting towards humans or other cats (usually close relatives) while half-raised shows less pleasure, and unhappiness is indicated with a tail held low. A scared or surprised cat may puff up its tail and the hair along its back may stand straight up and turn its body sideways to a threat in order to increase its apparent size. Tailless cats, such as the Manx, who possess only a small stub of a tail move the stub around as though they possessed a full tail, though it is not nearly as communicative as that of a fully tailed cat. Touching noses is a friendly greeting for cats, while a lowered head is a sign of submission. Some cats will rub their faces along their guardian's cheek or ankles as a friendly greeting or sign of affection. T

his action is also sometimes a way of "marking their territory," leaving a scent from the scent glands located in the cat's cheek.Cats also lick both each other and people (e.g. their owners). Cats lick each other to groom each other and to bond together (this grooming is usually done between cats that know each other very well). They will also sometimes lick people for similar reasons, that is, to "groom" them and to show them caring and affection. When cats are happy, they are known to paw their guardian, or that on which they sit, with a kneading motion. Cats often use this action alongside purring to show contentment and affection for their guardians or other times it can be when the cat is in pain or dying it is said to be a way of comforting itself. In the vernacular this action is often referred to as puddies, making muffins, paddy-pawing, happy feet, playing the piano, stromping, treading paws, or most commonly, kneading. It is instinctive to cats, which use it when they are young to stimulate the mother cat's breast to release milk during nursing. As a result, cats hand-raised by humans may lack this reflex. Pawing is also a way for cats to mark their territory. The scent glands on the underside of their paws release small amounts of scent onto the person or object being pawed, marking it as "theirs" in the same way they would urinate to mark their territory.Yawning in front of their owner and blinking behavior is common in cats and may be a sign of trust or affection. Some cats will respond to a human who dramatically yawns or closes and opens their eyes by reciprocating the action.