Agatha Christie (September 15, 1890 to January 12, 1976) was the prolific English author of detective stories. Sixty-six novels according to the Guiness Book of World Records. There are naturally cats in her stories, set as the tales are among various social classes and locales. These excerpts speak to the integral part cats can play in her work:
"The window was open just wide enough for a cat to get through.” “But it was not fixed in that position." ... “Yes, but I know it was a cat.” “You did not see a cat?” Blake said perplexedly and slowly: “No, I did not see it..." (Five Little Pigs)
'The cat,' declaimed Poirot, 'was worshipped by the ancient Egyptians. It is still regarded as a symbol of good luck'...("The Adventure of the Cheap Flat".)
It is part of the cat. 'It can't be. It's a black cat.' 'A black cat, yes, but you see the tip of the black cat's tail happens to be white.' 'Why, so it does! How clever of you!' (Evil Under the Sun)
In fact cats are not a typically critical element in Christie's stories, even though -- cats were her first audience. She mentions this in her autobiography, Agatha Christie: An Autobiography.(1977). As a child, she told stories to "the kittens in the garden."
And as time goes by, one is ever more appreciative of having a positive role model in Miss Marple, for being a snoopy old lady.