We had problems with covered litter boxes. Lamoni would stay in the liter box and keep Fifi out. Then she would get on top of it and keep him in. Finally she would go on top of the box. What a mess.

We did the one box per cat trick and put the boxes in opposite ends of the house. When we would change them, Lamoni would make sure that he marked each box by using it. Fifi would not go in a box that he had recently used.

We had two covered boxes fo a while. One would trap the other in a box. They became afraid of using the box because the other cat was always waiting just outside the box to attack. Off came the covers.

We would watch for the cats to use the box and then scold the other cat if interference was about to take place.

Now our LitterMaid sits in the attacked garage and scoops away.