I've come across something interesting and a little off putting. Previously, my exposure to the Green Ember series has been primarily through the Audiobook versions. However, I am now the proud owner of print copies of all six published books. As I was going through the first one, however, I discovered that the text in the print version does not exactly match everything I remember from the audiobook, which I listened to again quite recently. For example, the audiobook specifically names rats and bats among the beasts who pursue the Longtreaders and Smalls through seven mounds, while the print book refers only to "creatures" and mentions that some of them have wings.