What’s the weirdest thing you learned this week? Well, whatever it is, we promise you’ll have an even weirder answer if you listen to PopSci’s hit podcast.
The Weirdest Thing I Learned This Week hits Apple, Spotify, YouTube, and everywhere else you listen to podcasts every-other Wednesday morning. It’s your new favorite source for the strangest science-adjacent facts, figures, and Wikipedia spirals the editors of Popular Science can muster. If you like the stories in this post, we guarantee you’ll love the show.
FACT: You’re not allowed to keep bird feathers you find on hikes, and it’s all thanks to two women who got really mad about hats
By Liz Clayton Fuller
In 1886, ornithologist Frank Chapman went birdwatching in an uptown New York shopping district—but he wasn’t looking to spot living birds. He wanted to see how many different avians he could find on people’s hats.
He counted 542 hats adorned with parts from 174 different bird species. This wasn’t unusual: 19th-century women were obsessed with elaborate feathered hats featuring everything from woodpeckers and blue jays to egret plumes, vulture wings, and entire stuffed birds. Egret feathers were especially prized at $32 per ounce (twice the price of gold) because they only grow during nesting season. Hunters would massacre entire colonies during this vulnerable period, wiping out two generations at once.
Enter Harriet Hemenway and her cousin Minna Hall, two Boston socialites who read about the egret slaughter and decided enough was enough. They started hosting tea parties to persuade fellow wealthy Bostonians to boycott feathered hats, growing their movement to 900 influential boycotters. This activism evolved into the formation of the Massachusetts Audubon Society.
Their campaign influenced the Lacey Act of 1900, inspired Teddy Roosevelt to establish the first federal bird reservations, and ultimately led to the Migratory Bird Treaty Act of 1918. That law made it illegal to “pursue, hunt, take, capture, kill, possess, sell, purchase, barter, import, export, or transport” any migratory bird or their parts—including feathers you find on the ground. There’s no exemption for molted feathers or roadkill. The only exceptions are for legally hunted waterfowl, game birds like turkeys, and indigenous peoples for subsistence and cultural practices. Listen to learn why the term “sneaker” exists, and why we’re always one feather collection away from returning to the bird hat apocalypse.
FACT: Rabbits with “tentacle horns” helped scientists develop the HPV vaccine
By Jess Boddy
If you saw photos of rabbits with horns growing out of their heads this summer, don’t panic—it’s actually been happening for ages. Back in 1933, virologist Richard Shope discovered what causes it while rabbit hunting in New Jersey. The cottontail rabbit papillomavirus (CRPV) makes rabbits grow real horns made of keratin, mostly on their heads but sometimes on their faces. It’s usually benign and the growths eventually fall off, though in rare cases it can turn cancerous or interfere with eating and vision.
Shope was already famous for isolating influenza A in pigs when he started studying these horn-faced bunnies. His discovery was pretty foundational for understanding transmissible cancers. But the real kicker is that understanding how CRPV worked in rabbits helped scientists figure out how certain strains of human papillomavirus (HPV) cause cervical cancer. That connection directly led to the development of the HPV vaccine.
FACT: Traditional yogurt makers used ants to make their starter cultures, and fancy restaurants are bringing it back
By Rachel Feltman
Before commercial yogurt production standardized everything with a couple of reliable bacterial strains, people sometimes had to get creative with their fermentation starters. In the Balkans and Turkey, some traditional recipes called for dropping ants into warm milk, covering it with cheesecloth, and burying the whole thing in an ant mound overnight. The heat from the colony’s activity creates the perfect incubation temperature, and redwood ants naturally carry lactic acid bacteria on their bodies—plus the formic acid they produce as a defense mechanism helps lower the milk’s pH to create an ideal bacterial environment.
This ancient technique recently caught the attention of chefs at Alchemist, a two-Michelin-star restaurant in Copenhagen, after someone noticed that milk with an ant in it started curdling in the fridge. They partnered with researchers who traveled to a Bulgarian village to recreate the traditional method, and it worked perfectly. The ants bring everything you need: the right bacteria, the perfect pH conditions, and built-in temperature control from their colony.
The resulting yogurt made it onto Alchemist’s menu as an ant-shaped ice cream sandwich and a milk-washed cocktail with surprisingly mild acidity and fruity notes. While you shouldn’t try this at home (ants can carry parasites), the research highlights how traditional fermentation methods used diverse microbial communities for more complex flavors.
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