Humans have been digging deep holes for fun and profit since time began, and some animals have been doing it for way longer than that! And all of those holes can't hold a candle to some of the natural holes the Earth's got going on. And those are nothing compared to space, which some (Sam) would argue is the biggest hole of all!

Follow us on Twitter @SciShowTangents, where we’ll tweet out topics for upcoming episodes and you can ask the science couch questions! 

While you're at it, check out the Tangents crew on Twitter: Stefan: @itsmestefanchin Ceri: @ceriley Sam: @slamschultz Hank: @hankgreen

If you want to learn more about any of our main topics, check out these links!

[Truth or Fail]

Termite mounds: https://www.cell.com/current-biology/fulltext/S0960-9822(18)31287-9?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0960982218312879%3Fshowall%3Dtrue

Band of holes: https://www.sciencealert.com/is-this-mile-long-strip-of-holes-an-ancient-inca-tax-system

Molecular drills: https://pubs.acs.org/doi/10.1021/acsami.9b22595#

Roman skin cream: http://cenblog.org/artful-science/2013/01/14/ancient-roman-cosmetics-skin-cream-from-the-2nd-century-a-d/

[Fact Off]

Ant colony fallen through hole

Pictures in this paper: https://jhr.pensoft.net/articles.php?id=9096&display_type=element&element_type=4&element_id=43&element_name=

https://link.springer.com/article/10.1007/s000400050022

https://arstechnica.com/science/2016/09/bizarre-ant-colony-discovered-in-an-abandoned-polish-nuclear-weapons-bunker/

https://www.popsci.com/story/science/ant-colony-escape/

https://jhr.pensoft.net/article/38972/

Star-nosed mole nose holes

The video!

https://www.youtube.com/watch?v=UMz0Q7VbT9w

https://news.vanderbilt.edu/2006/12/20/scientist-discovers-some-mammals-can-smell-objects-under-water-58788/

https://www.nytimes.com/2006/12/26/science/26bubble.html

https://www.newscientist.com/article/dn10834-star-nosed-mole-can-sniff-underwater-videos-reveal/

https://www.sciencedaily.com/releases/2017/11/171120090051.htm

https://www.sciencedaily.com/releases/2017/04/170424084028.htm

[Ask the Science Couch]

Sinkholes / blue holes

https://www.whoi.edu/oceanus/feature/blue-holes-and-hurricanes/

http://geology.wlu.edu/intro3d/sinkhole/sinkhole.html

https://www.usgs.gov/special-topic/water-science-school/science/sinkholes?qt-science_center_objects=0#qt-science_center_objects

https://www.smithsonianmag.com/smart-news/explore-worlds-deepest-blue-holes-180959977/

Flooded pit caves

https://www.theguardian.com/world/2016/sep/30/worlds-deepest-underwater-cave-found-czech-republic-hranice-abyss

https://www.nationalgeographic.com/adventure/destinations/europe/czech-republic/deepest-underwater-cave-discovered/

Mariana trench

https://www.nationalgeographic.org/activity/mariana-trench-deepest-place-earth/

Kola Superdeep Borehole

https://www.smithsonianmag.com/smithsonian-institution/ask-smithsonian-whats-deepest-hole-ever-dug-180954349/

[Butt One More Thing]

Scorpion anus

https://www.sciencemag.org/news/2015/01/when-attacked-some-scorpions-discard-their-stinger-and-their-anus