In captivity, indoor cats typically live 14 to 20 years, though the oldest-known cat lived to age 36. Domesticated cats tend to live longer if they are not permitted to go outdoors (reducing the risk of injury from fights or accidents and exposure to diseases) and if they are neutered. Some such benefits are: castrated male cats cannot develop testicular cancer, spayed female cats cannot develop ovarian cancer, and both have a reduced risk of mammary cancer.

Like some other domesticated animals, cats live in a mutualistic arrangement with humans. It is believed that the benefit of removing rats and mice from humans' food stores outweighed the trouble of extending the protection of a human settlement to a formerly wild animal, almost certainly for humans who had adopted a farming economy. Unlike the dog, which also hunts and kills rodents, the cat does not eat grains, fruits, or vegetables.

A human with a good relationship to a cat, where there is trust and good communication, can find a cat to be as trainable as a dog. Like dogs and people, many cats have active minds that thrive on stimulation, exploration and learning. Many of the same basic methods of training a dog-- shaping behavior, giving treats for correct responses, and lavish praise and attention-- work extremely well when training a cat.

Teaching a cat to "sit" for treats or meals is quite easy and gives a good base for further training. When training a cat, it is important to remember that like humans, cats will not continue to obey commands if their attention is elsewhere. They may become frustrated or bored, as humans do when trying to learn something new or difficult. When the cat's attention starts to wander, training time is over. However, their fine memory ensures that further training can compound. Cats are social animals, usually living in family packs. In a domestic situation, the human family becomes their 'pack'. If the cat has a good emotional relationship with their owners, training can be a fun "game".

Cat litter (often called kitty litter) is one of any of a number of materials used in litter boxes to absorb moisture from cat feces and urine, which reduces foul odors such as ammonia and renders them more tolerable within the home.

Several kinds of cat litter are commercially available, enabling consumers to decide which factors are most important. Some cat owners are concerned about litter being tracked throughout the house, while others may look for litters that are biodegradable. Absorbency, odor control, texture, safety and cost are other considerations.