When I was involved in the rat shows, there were some people who were setting up agility courses to train their rats on. I never got into that, because i was too lazy to train my rats (put too much time into training my horse and dogs, rats are much easier to handle even without that kind of extensive training! lol), but I have had a few "trained" rats that would come when called and used a litter box. That was about the extent of my rat training career.