Here in the Study you will find the results of the cats' play activities! That would include headless mice, hairballs (be careful if you're walking around in bare feet), shredded plum blossoms and many, many kittens.

Old Japanese proverb say: Inu o mikka kaeba san-nen on o wasurenu, neko wa san-nen katte mikka de on o wasureru. (Feed a dog for three days and it is grateful for three years. Feed a cat for three years and it forgets after three days.)