The experiment in this video was requested by one of our loyal viewers. The Request "I want to see how they react to an optical illusion and/or the concept of infinity." The Setup "Buy a very good quality 'infinity' mirror and (depending on whether you can seal it or otherwise make it function underwater or not) either put it in the tank or directly outside the tank, to see how the octopus reacts to seeing it." Hypothesis "The octopus could ignore the infinity mirror completely, it could investigate it for a while then ignore it after that, it could try to get inside it, it could become scared and hide, it could try to destroy the infinity mirror." This was a very interesting and fun request. We watched the video that was sent to us on infinity mirrors, and many other DIY videos. We immediately sprung into action and started working on building an infinity mirror. After a few failed attempts, we got the required optical illusion. Initially, we planned on putting the mirror directly into the tank. We made a mirror that was completely waterproof and placed it in the water. Everything was fine except for the fact that the illusion was not as obvious underwater. We then tested it on the outside of the tank and seemed to have a much clearer "tunnel". So for this experiment, the infinity mirror was on the outside of the backside of the tank. All that was left was to see whether or not Michael, our octopus, would ignore the tunnel, or attempt to go through it! Michael spent a little over an hour in the tank with the infinity mirror. Approximately 10 minutes into the experiment, he no longer showed any interest in the infinity mirror. We repeated the experiment the following day with the same octopus, and he continued to basically ignore it. Thanks for sending in your request. If there is a follow up experiment you'd like to see with the infinity mirror, we'd love to hear about it.