Owning a cat involves a lot of deciphering body language, whether the rapid swaying of the cutie's tail or the visibility of her stomach. While tail motion often signifies an unhappy feline, bellies on show frequently point to the polar opposite -- a cat who feels peaceful and confident.
Cats naturally feel helpless when their stomachs are visible and therefore accessible to others. Out in nature, being on their backs is their most defenseless position in the event of predator attack. If your cat has her belly showing, it means she's not on "lookout" at the moment. She's not presently worried about anything bad happening. She's lounging around and feels truly cozy and secure in her environment. She essentially owns the world.
A cat's unadulterated tranquility also comes with another message -- one of full trust in you and anyone else who might be in her vicinity at the time. If a cat ever allows you to see her belly, it typically means that she trusts you in and out and knows from experience that you're not going to ever cause her any detriment. This, in a way, is the ultimate expression of a cat-human bond. Your cat is basically conveying to you that she knows that you're on her side, and that she's aware you're not one of the bad guys.
If a cat is on her back showing you her belly, it could mean that she's just pleased to see you, pure and simple. Perhaps you've been out of the house for a few hours running errands and your cat is excitedly welcoming you back into your abode. She missed your comforting company.
Belly Shows Between Felines
When felines are on their backs with all of their feet pointing upward, it generally denotes the desire for playtime. If Sadie assumes this position when she sees Skitch saunter into the room, it usually means that she's in a spirited, energetic mood and wants to have a little fun. Kittens and adult cats alike frequently do this to request play.
Although a show of the belly usually is a positive thing, it's important to approach these types of situations carefully. Cats' bellies are delicate spots for them. If your cat lets you see hers, it definitely doesn't mean that she wants you to pet it a la canines. It just means that she's in a comfort zone with you. If you break her out of her relaxation mode by trying to stroke her stomach, she just might react by growling or swatting at you. Let your kitty revel in her peaceful time, and never assume that a tummy show is asking for a belly massage.
Context means everything as far as cat body language is concerned. It your cat's on her back with her tummy showing, be alert to anything else she might be doing simultaneously. If you hear any growling or her ears are pushed back, it probably is a sign that she's preparing to attack.