Hi all - not sure yet how to use this forum, but I guess I will learn as I go along. I just recently got 2 male rats for my 16-year old son and we love them. They have so much character and love people. One of my concerns is that I read a lot about letting them out to run around cardboard boxes, but we are so afraid they will get away and we won't be able to get them back. Any advice would be great. These rats have tons of energy and look like they really need to get out of the cage and explore and run.