Keith is on the road at Midland College in Midland TX, and he takes the time to talk with Lou Densmore, chair of the Biological Sciences Department at Texas Tech in Lubbock TX. He talks about his interest in the population diversity of crocodiles & alligators in single populations, and why invasive species can be harmful to those populations. Densmore also offers some helpful hints for how to tell crocodiles from alligators. Aired Oct. 21, 2012.