Tremors is about a group of people in the tiny Nevada town of Perfection who encounter large, subterranean worm-like creatures called Graboids, which are attracted to sound.  In this episode, we attempt to explain the biology of these creatures, including their incredible locomotive abilities, bulletproof head, and mouth tentacles.  We also take a look at seismology, and how sound can actually tell you where these creatures are.  Plus we talk about Dennin’s underground bunker, Daniel J. Glenn’s fascination with elephant guns, and Ben’s strategy for making graboid-proof walls.