March 06, 2026

Snail Sex Tape

29 minutes

In this episode, we consider a creature we often don’t think much about—the snail. And not just snails, but their sex lives. Which, as it turns out, is epic. There is persuasion and subterfuge, spaghetti penises and co-copulation. And this very surprising habit—erm kink—of making tiny arrows (actually!) and stabbing each other with them. Known as a “love dart,” these limestone daggers aren’t just a strange trick of nature—they have a deep evolutionary purpose.

Special thanks to Menno Schilthuizen and Aaron Chase.

EPISODE CREDITS:

Hosted by - Molly Webster

Reported by - Molly Webster

Produced by - Mona Madgavkar, Annie McEwen, Molly Webster

Sound design contributed by - Mona Madgavkar, Annie McEwen

Fact-checking by - Diane A. Kelly

and Edited by - Alex Neason

EPISODE CITATIONS:

Videos -
A love dart being DARTED! (https://zpr.io/rYhLwXhaxQQP) – Molly has watched this video so many times

Articles -

Changes in the reproductive system of the snail Helix aspersa caused by mucus from the love dart. (https://zpr.io/xxjuCcTyiVJV) by Koene JM, Chase R. J Exp Biol.

The snail's love-dart delivers mucus to increase paternity. By Chase R, Blanchard KC. Proc Biol Sci.

A love-dart at the heart of sexual conflict in snails (https://zpr.io/X2ANHPaEg5sr) by Foote C

** This article has an image of eight different love darts, and it’s what Molly shows to Soren in the episode (this image is one of her favorite research finds!)

Books -

“Nature’s Nether Regions: What the Sex Lives of Bugs, Birds, and Beasts Tell Us About Evolution, Biodiversity, and Ourselves” (https://zpr.io/ktMvJbZciCdD) by evolutionary biologist Menno Schilthuizen.

Signup for our newsletter!! It includes short essays, recommendations, and details about other ways to interact with the show. Sign up (https://radiolab.org/newsletter)!

Radiolab is supported by listeners like you. Support Radiolab by becoming a member of The Lab (https://members.radiolab.org/) today.

Follow our show on Instagram, Twitter and Facebook @radiolab, and share your thoughts with us by emailing [email protected].

Leadership support for Radiolab’s science programming is provided by the Simons Foundation and the John Templeton Foundation. Foundational support for Radiolab was provided by the Alfred P. Sloan Foundation.

Hosted by Simplecast, an AdsWizz company. See pcm.adswizz.com for information about our collection and use of personal data for advertising.

...more

View all episodes

By WNYC Studios

4.6

4232242,322 ratings