I have 4 house cats and I doubt that would kill anything. A mouse could probably take over their food bowl.
I Live in a trailer park with many feral cats. They feast on the mice that come in from the fields and birds. Cats are natural hunters. Have you ever seen a cat eat a mouse—they get a weird look on their face like its a narcotic. One they eat one mouse, they want more only eating cat food if they must.