Cats and kittens should be acquired in pairs whenever possible. Tylenol and chocolate are both poisonous to cats. Cats scratch to shed the sheaths of their old claws. Orange and lemon rinds are offensive to cats. A light rubbing of orange peel on furniture will discourage your cat from using it as a scratching post.
Cats also hate the smell of vinegar.
Because of rigorous show standards, it's possible that some purebred cats will become extinct over time because of relentless inbreeding. Strict standards for certain breeds prohibit diluting that gene pool with related cat species. The upshoot is that inbreeding can produce cats with undesirable, even fatally flawed genetic characteristics. The healthiest, toughest, most resilient domestic cat is the common interbred house cat. The standing of cats in human history runs the gamut from the worship of cats by the Egyptians to the execution of people who housed cats in the Middle Ages - a particularly rough period when cats were associated with evil.