No matter how cute and innocent your cat may look, it's not easy to deny her natural and learned predatory instincts. If your cat's favorite pastime seems to be annihilating a mouse and then presenting it to you proudly as a gift, don't be annoyed. Cats will be cats!
From birth, cats possess the instinct to hunt and run after their prey. When it comes to actually killing for a meal, however, that behavior is generally mimicked from closely observing the mama cat.
Chasing is a natural and healthy feline activity that usually begins with the littermates. As wee kittens, cats learn how to ambush their "victims" and run rapidly and handily -- all while honing their coordination skills.
Early on, queen cats who live or spend a lot of time outdoors teach their kittens about killing for food. For example, if mama kills a mouse, squirrel or bird, she will probably bring it back to her litter and devour it in front of them -- a key lesson for the little ones. Eventually after some time passes, mama will bring her prey to her kittens, and allow them to eat it instead -- success.
If you're puzzled as to why your house cat seems to like torturing her mice, it may be because she's feeling uncertain about the whole thing. She may want to be 100 percent sure that the mouse is totally dead. After all, the last thing she probably wants is for the little rodent to come back to life and retaliate -- yikes! In a way, incessantly torturing a mouse is a form of self-defense, feline style.
If the mouse-torturer in question is an indoor cat who has never resided outside, even as a kitten, then the torture factor could be related to pure pleasure. After all, cats aren't born with the innate desire to kill their prey. The killing part is copied and learned from the mother. However, cats are indeed born wanting to chase after things. When a cat is endlessly mutilating a now-dead mouse, it may simply be because she's playing with it like a toy or a game. She also may be pretty proud of her catch, plain and simple.
Outdoor Cats and Indoor Cats
For the most part, outdoor cats do not play around or "torture" their prey -- mice included. Once an outdoor feline kills a mouse, she typically consumes it, no time wasted. When an indoor cat does the same thing, however, her drive to chase likely isn't related to hunger at all. When it comes to prey-hunting behavioral patterns, indoor and outdoor cats are in many ways like night and day, and unsurprisingly so.