Why Couldn't the Shriekers Feel the Ground? Pedro's Truck Told You.

It's getting hot in here. Another day in the yard!!!! In Tremors, a graboid could feel a single footstep through solid ground. In Tremors 2: Aftershocks, Earl Bassett walks through a warehouse full of Shriekers, close enough to touch, and none of them goes for him. So why couldn't the Shriekers feel the ground? The movie tells you a quarter of an hour before anybody explains it: Pedro's truck stops in the dark, and the engine has been torn open and is still steaming. Then the radio station. Then the car they hot-wire. Everybody thinks the Shriekers are geniuses. Burt works it out at 69:15: infrared. And Kate names the real animal that does it: the rattlesnake. We also answer three of your comments from the Graboid video: should Burt and Heather have gone deaf in that basement (the real decibels, eardrums and hearing loss), was the last graboid really the one that lost a tongue to the truck (yes, and the film tells you twice), and which origin theory we're pinning. Verdict: HEAT. CHAPTERS 0:00 Intro 0:54 Earl's ostrich ranch, and a sequel that almost wasn't 2:45 Burt, and should they have gone deaf in that basement? 4:51 The last graboid's missing tongue 5:51 The graboid that got sick, and why animals swap senses 7:28 The clues: an engine, a radio station and a car 9:23 Infrared: rattlesnakes, vampire bats and squirrels 12:19 How to hide from heat 14:46 Precambrian, the origin answer we pinned, and the verdict Narrated by: Me :) SOURCES - Tremors 2: Aftershocks (1996), dir. S. S. Wilson; Tremors (1990), dir. Ron Underwood. Every timecode quoted is from the films. - Gracheva EO et al., Julius D. "Molecular basis of infrared detection by snakes." Nature 464:1006-1011 (2010). doi:10.1038/nature08943 - Gracheva EO et al., Julius D. "Ganglion-specific splicing of TRPV1 underlies infrared sensation in vampire bats." Nature 476:88-91 (2011). doi:10.1038/nature10245 - Rundus AS, Owings DH, Joshi SS, Chinn E, Giannini N. "Ground squirrels use an infrared signal to deter rattlesnake predation." PNAS 104:14372-14376 (2007). doi:10.1073/pnas.0702599104 - Wahnschaffe U, Bartsch U, Fritzsch B. "Metamorphic changes within the lateral-line system of Anura." Anatomy and Embryology 175:431-442 (1987). doi:10.1007/bf00309679 - O'Connell-Rodwell CE. "Keeping an 'ear' to the ground: seismic communication in elephants." Physiology 22:287-294 (2007). doi:10.1152/physiol.00008.2007 - Meinke DK, Finan DS, Flamme GA, Murphy WJ, Stewart M, Lankford JE, Tasko S. "Prevention of Noise-Induced Hearing Loss from Recreational Firearms." Seminars in Hearing 38:267-281 (2017). doi:10.1055/s-0037-1606323 - Cho SI et al. "Mechanisms of Hearing Loss after Blast Injury to the Ear." PLOS ONE 8(7):e67618 (2013) - NIDCD (National Institutes of Health), "Noise-Induced Hearing Loss" - Fangoria #91 (April 1990), Ron Underwood interview, as reprinted in the Arrow Video Tremors booklet - Burt's guns: Internet Movie Firearms Database (IMFDb), Tremors and Tremors 2: Aftershocks, checked against Burt's own lines in the films - Tremors 2 production history: Wikipedia, "Tremors 2: Aftershocks"; the studio's own behind-the-scenes film ("Beneath The Surface") - Dry ice: Wikipedia, "Dry ice" FOOTAGE Film clips are used under fair use for commentary and criticism: Tremors 2: Aftershocks (1996) and Tremors (1990). Clips and footage via: Tremors (official channel, "The Making of Tremors 2"), Centers for Disease Control and Prevention (CDC / NIOSH), National Science Foundation News ("Seeing Heat", Science Nation), BBC Earth, Nat Geo Animals, Deep Look (PBS / KQED), iBiology Science Stories, Science News, New Scientist, thermalvideo, Engineering Explained, AstroCamp, NatureNorth, Atlas Animal. Photos: Yale School of Medicine (Elena Gracheva); Larissa Block / Wikimedia Commons (Ron Underwood).