Porcupine in a levee den (IMAGE) American Geophysical Union Caption Animals such as porcupines that make their dens in the walls of levees can weaken the infrastructure to the point of collapse and flooding, according to new research in Water Resources Research. Credit Matteo Balistrocchi Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.