This roundup of some of the most unique excrement in the animal kingdom, showcasing the fascinating diversity of animal waste, includes a 2018 Georgia Tech study of how wombats manage to produce square-shaped feces. The study's authors include David Hu, professor in the School of Biological Sciences and the George W. Woodruff School of Mechanical Engineering, with an adjunct appointment in the School of Physics. As it turns out, the elastic nature of the marsupial's intestinal walls is a key factor.