Biology
How Gut Microbiota Enable Herbivorous Mammals to Thrive on a Plant Diet
Quick fact
A single cow's rumen contains more than 100 billion microbes per milliliter, and these microbes produce up to 70% of the cow's daily energy as volatile fatty acids.
Why this is interesting
You might think a cow's stomach is just a large bag for grass—but it's actually a fermentation vat teeming with trillions of microbes. How does this invisible workforce allow herbivores to survive on a diet that would starve us?