Why do fireflies flash their lights on and off, on and off? That’s what four curious kids want to know. Biologist Sara Lewis has studied fireflies for decades, and she’s cracked the code of their spectacular light displays. She explains why fireflies light up at night with a story of an undercover experiment. Sara tells us how she “spoke firefly” and learned that female fireflies are surprisingly hard to please. To learn more about fireflies, see Sara’s website and book at www.silentsparks.com. We're proud that Tumble is a free podcast! But we need your support to keep it going and growing. We’ve launched a Patreon campaign to offer you awesome rewards in exchange for a monthly pledge! Find out what our next episode is about in advance, get notified of opportunities to be on the show, receive exclusive educational content and so much more. Find the link on our website, www.tumblepodcast.com. Subscribe and review Tumble on iTunes, like us on Facebook, and follow us on Twitter. We want to hear from you at [email protected]. Firefly photo by Terry Priest used with permission from Sara Lewis.