In the wild, cats are used to roaming freely and interacting with animals, plants, and dirt. Unfortunately, letting a cat roam freely outside exposes it to all types of dangers from cars and chemicals to malicious people and animals like dogs.
So if you have an indoor cat, give it stimulation in the form of a window where it can peer out at the whole wide world outside. Also consider getting lots of cat posts and houses to put around your home so your cat can explore them. You might also consider building a catio so your cat can get the excitement of going outside with the safety of staying inside. By being creative, you can provide enough mental stimulation for your cat in your home.
To learn different ways to stimulate an indoor cat, click here.