Radiolab for Kids The Slowpoke: How Sloths Grow Invisibility
Dec 18, 2025
Zoologist Lucy Cooke, an expert on sloths, shares fascinating insights about their slowness as an adaptive strategy rather than laziness. She narrates the remarkable journey of a sloth named Nacho and explores how sloths employ camouflage for survival against predators like harpy eagles. Joining her is Dr. Sammy Ramsey, who reveals the unique ecosystem of moths, mites, and fungi that thrive in sloth fur, showcasing a symbiotic relationship that enhances their invisibility in the wild. Together, they highlight the importance of conservation for these captivating creatures.
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Nacho Keeps Coming Back
- Nacho the sloth repeatedly returned to a beachfront nightclub area after being relocated two miles away.
- Jose Pablo Guzmán García and his team stopped trying to move him and now focus on human-sloth coexistence.
Slowness As An Energy Strategy
- Sloths are slow primarily to save energy because leaves provide little usable energy.
- Their specialized guts host bacteria that let them eat toxic leaves other animals avoid.
Mangrove Hunt For Pygmy Sloths
- Lucy Cooke recounts a grueling mangrove expedition to find pygmy sloths, enduring storms, mud, and snakes.
- After long searching they finally spotted a tiny pygmy sloth perfectly camouflaged high in the canopy.