Those who have pets at home know how hard it is to train them to do what you want. It concerns not only tricks, but such usual things as going to toilet in one certain place, and not bringing food to other rooms, but to eat that where they are supposed to eat. I have a cat at home, so I faced this problem to a full extend. I think that some kind of transmitter might be invented, sending encoded signals to animal's brain. This transmitter would be installed in places needed, and using different signals attracted animal. After some time they could be removed, because animal would memorize already what is needed.