This form of communication in cats includes a great range of signals involving body language and specific postures; eye contact; and lasting visual signs such as scratch marks on objects of significance.
As humans we tend to notice the obvious body language cues from our cats; as if reading capital letters of the written word. Paying attention to smaller details may help us to read the fine print of their moods and better understand this subtle and intricate language.
Generally a cat in an aggressor stance will puff up and hold itself tall to appear larger; while a cat in a defensive position will seem to shrink by holding the ears and tail close to its body, and withdrawing the head close to the shoulders.
Feline body language is much more nuanced than that in dogs. While dogs may wag or drop their tails; a cat’s tail stands out in the natural world as a remarkable instrument of expression. When held upright it indicates a friendly approach, but it will fluff up like a toilet brush in aggression. The tail is held stiffly behind or lashed from side to side to show offense; or wraps closely around the body in a defensive stance.
Ear position is also an important aspect of visual communication in cats. Flattened ears indicate fear and defensiveness; ears held sideways can show conflicting emotions or anxiety; and turned back ears are a sign of aggression. Rolling on the ground by a female to male cat can be a type of feline flirtation, while between males it is seen as a sign of appeasement(2). When directed towards humans, rolling is seen as a friendly or playful interaction. (For dog owners it’s easy to misinterpret this as an invitation for a belly rub… Good luck with that!)
Cats that are trying to avoid confrontation will generally not engage in direct eye contact, as this can be perceived as threatening. However, context changes everything; as in friendly encounters eye contact can be peacefully maintained, and a stare with slow blinks is believed to show trust and affection(1).
Pupil size varies according to ambient light, with bright conditions causing constriction, and dim light leading to dilation. However, pupil size can also change in response to pain or according to emotional state. This can be difficult to interpret. Cats' pupils may constrict in situations of arousal such as aggression, fear, predatory play or pleasure. Pupils may dilate in fear, anxiety, surprise or excitement. It's helpful to interpret pupil size in relation to other body language cues.
Claw scratching leaves both a visual and a scent marking; and is understood to be used for both navigation purposes along regular routes(2) as well as for increasing a sense of security and familiarity to an area.