Bees could build flat honeycombs from just three shapes: squares, triangles or hexagons. But for some reason, bees choose hexagons. Always "perfect" hexagons. Why?
Illustration: Robert Krulwich/NPR
At NPR headquarters, our green roof — covered with soil and plants — houses two small wooden hives with more than 20,000 bees. No honey yet, but they are buzzz-y over on twitter @NPRBees. — tanya b.