Hello there Akiko! I believe your concept of receiving just one device and find out to start with if all of them get used to the Litter Robotic it’s a good method. Then, if you see them all utilizing it, you can purchase a next one particular. One one device https://automatic-litter-box22119.blogdosaga.com/36895938/not-known-factual-statements-about-automatic-litter-box