how do they stay entertained

How does your kitten or cat stay entertained. Well I have a new kitten in the home. I've made previous discussions about her. We have changed her name a lot of times and now we are down to one name change and that's it. Her name is kelly and my older cats name is alexia. Alexia likes to stay entertained by chasing around balls, tossing toy mice in the air and pouncing on a ball that is attached to a spring. The newcomer kelly keeps entertained playing around with her toy mouse and playing withh paper and sometimes seeing what alexia is up to. So how does ur kittens oe cats stay entertained.