As creepy as it may be for the owner when cats come home with dead animals/insects, you cannot get mad at them. In fact, praise them, tell them thank you. Because when a cat kills an animal for you, it means they love you, and are eternally grateful for the life you’ve given them. It’s the most honorable thing you could possibly receive from your kitty.
This is technically true, in that it is a gift. But they’re not actually showing eternal gratitude for the life you’ve “given” them. They don’t know or care about that. They’re proving to you what good hunters they are, because they want you to know that they are better than you. When mother cats are raising their kittens, they show them how to hunt. They catch food and bring it to them. That’s essentially what cats are doing when they bring you “gifts”. They’re showing you. They’re saying, “See, human? This is how you do it. I killed this, because you can not. Watch me closely, and perhaps one day you can be as ruthless a killer as myself. Good luck, human. Now go scoop up my poop. Meow.”