It may have happened when you locked eyes with your secret crush, or before an important job interview, but what exactly caused that strange, fluttering sensation in your stomach? Hosted by: Hank Green Head to scishowfinds.com/ for hand selected artifacts of the universe! ---------- Support SciShow by becoming a patron on Patreon: www.patreon.com/scishow ---------- Dooblydoo thanks go to the following Patreon supporters: Lazarus G, Sam Lutfi, Nicholas Smith, D.A. Noe, alexander wadsworth, سلطان الخليفي, Piya Shedden, KatieMarie Magnone, Scott Satovsky Jr, Charles Southerland, Bader AlGhamdi, James Harshaw, Patrick D. Ashmore, Candy, Tim Curwick, charles george, Saul, Mark Terrio-Cameron, Viraansh Bhanushali, Kevin Bealer, Philippe von Bergen, Chris Peters, Justin Lentz ---------- Looking for SciShow elsewhere on the internet? Facebook: www.facebook.com/scishow Twitter: www.twitter.com/scishow Tumblr: scishow.tumblr.com Instagram: instagram.com/thescishow ---------- Sources: www.msdmanuals.com/en-gb/home/brain,-spinal-cord,-and-nerve-disorders/autonomic-nervous-system-disorders/overview-of-the-autonomic-nervous-system news.nationalgeographic.com/news/2006/03/0307_060307_human_prey.html journals.plos.org/plosone/article?id=10.1371/journal.pone.0152284 www.ncbi.nlm.nih.gov/pubmedhealth/PMHT0025458/ www.ncbi.nlm.nih.gov/pubmedhealth/PMHT0025459/ theconversation.com/explainer-why-do-we-get-butterflies-in-our-stomachs-72232 link.springer.com/chapter/10.1007/978-1-4939-0897-4_3 onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2982.2012.01906.x