We have two cats who are free range with a cat flap. We live next to fields and one of them is a very enthusiastic hunter. She has bells on her collar but that doesn't stop her. She mostly hunts at night and apart from the effect on the wildlife, I'm fed up of coming downstairs to a pile of rodent livers in the morning. I'm thinking of locking the flap overnight and keeping them in to see if it helps, but the problem is the flap is in our living room - it's in the patio door at the back of the room which opens on to the back garden. At night we shut the internal door so they can't go anywhere else in the house. There's nowhere else for a flap to go - there's no external door in the kitchen, only the living room patio door and the front door which can't have a flap in it. The problem is I don't particularly want a litter tray in my living room. We shut them in there because if we leave the internal door open they either come upstairs and yarl all night to get in the bedrooms, or claw the new stair carpet to bits. Do you think they could manage without a litter tray overnight? From about 11pm until 7am?