Put the tube in your rat's cage and watch them have fun! They will gnaw the tube and paper towel plugs to get at the treats within. The paper and cardboard are non-toxic and the rats can use the shreds as nesting material afterwards as well. It takes my rats about 5-10 minutes to access the treats. It encourages teamwork as well, as they will quickly discover that they can open the tube faster while working on it together than they can from repeatedly stealing it from each other. :) Enjoy!