Have got 2 lovely 8 month old kittens. Boy cat occasionally brings us worms which I can handle, but girl cat is a more proficient hunter and we've had a steady stream of mice and frogs over the last few weeks in varying states. I'm getting to the point where I've had enough so I'm thinking of keeping them in at night. Would this mean going back to a litter tray or would they be ok til the next morning? Are there any alternatives to keeping them in?