I asked a question a few months ago about my cat's behavior. I have a 9 month old male Persian Cat, and I wanted to know what I can do prevent stray cats entering my house premises and intimidating my pet. He doesn't really do much but gets easily frustrated and runs out of the house the first chance he gets. How can I stop stray cats entering the premises? I had him neutered on the advice of my vet, keshlam, and James Jenkins♦. However, that didn't stop them visiting and intimidating my cat. Please help on how I can stop this before my cat runs away and doesn't come back.
I will give a few options.
First, I would recommend you mix vinegar with lemon juice. (75% vinegar 25% lemon juice) I guarantee no cats will come near this stuff, you just have to apply every day in small amounts around your house's parameter. Keep in mind this will kill grass and other plants very quickly.
Another way is to make a smoothie. Yep, make a smoothie. In this smoothie, put bananas, cucumber, and assorted citrus. Dump this around the perimeter of your house and it should keep cats away. It still might kill grass.
Yet another way is to purchase some lemon-scented mosquito repellent strips, or spray and put them around the perimeter of your house. The spray will kill grass and plants. Still another way, is to put any Febreze product around the perimeter of the house. The spray will of course, kill plants and grass.
Another way is to mark your cat's territory. By this, I mean, yes, putting your cats "waste" around your house. This will let other cats know that this is his territory. Although I'm guessing you won't do this. Hope one of these helped.