Here is How to Make a Happy Indoor Cat!
There is no basis for the theory that your cat can only be happy if it goes out of the house. You can keep your kitty happy by playing with it, ensure the animal is kept stimulated and providing toys that entertain the animal. If the weather outside is a harsh one, then it is the responsibility of the cat owner to create an interesting indoor environment for your cat.
If you love an indoor cat, you should start from the time your kitty is young. Kittens accustomed to living inside a house are not keen to go out of it. To be doubly sure that your kitty does not leave the house, install a screened porch. You can buy a cat-specific enclosure like a "catio" so that the feline can enjoy the best of the outside without any of the risks. These fences are cat-specific and thus could be unable to stop other animals from entering the yard. You should be present when your cat plays outside the house in the yard. Before you allow the cat to go out, ensure the yard is cat-proof. The fence must have no escape routes. A good idea is to plant toxic shrubs, which will deter the cat from going towards the property borders.
In-case you are lucky to live in a peaceful neighborhood without the possibility of stray dogs, you can purchase a harness and train the cat to walk on a leash. Such training takes a lot of patience and time. It is easier to teach a kitten. Do not leave the kitten alone when they are tethered to a fixed position by their harness. Allow the cat to hang out. Install an indoor perch near to a window. You can start with a padded perch at any pet supply store. Another way is to install an enclosure that sits in a window frame. The larger perches could be attached to the house sides or the ground-floor apartment patio.
Get Cat Furniture
You can go for a ready-made "kitty condo" or cat tree. If you have the skill, you can make it yourself. A cat tree could be short or may stretch from the floor to the ceiling. It offers excellent climbing opportunities, and if you have more than one cat, creates play areas and rest areas by taking advantage of the vertical space. If possible, position the cat tree adjacent to a window so that the cat can observe any outside action. Do remember to play with your cat every day, Bring different kinds of toys which permit your cat to chase, pounce, stalk, and kick. When you two are done playing, store the toys which may harm the cat out of its reach.