I was using a Litter Mate box for years. I have 2 cats in home, 10 outside. I called customer support when I bought the Litter-Robot. My 2 cats inside would not touch it. I did what they said and it worked. I also new you have to wait and give them a chance. It's different to their world. Leave their old litter box next to the new one and let it get dirty. Sit with them and give treats near the box. I put the treats and catnip in a bowl and put it in box for a little bit. The best thing you can do is put their own smell in litter box, I scooped out what they left in the old box and it worked perfectly. I like the Litter-Robot now. It keeps smell under control and my 2 cats are using it!!!