Cats because they are generally quiet, mind their own business, don't require hours and hours of constant attention, and they don't usually crash into things. Cats can also more or less take care of themselves, while most domesticated dogs can't whatsoever. Forget to feed a cat? If it's hungry, it'll take incentive and eat bugs, birds, or rodents. Can't make it home every four hours to let your pet outside? No worries, a cat will use its box. Tired of having your belongings destroyed because you didn't have time to entertain your dog? Get a cat, because they're entertained by watching birds fly around outside or just laying around sleeping.