There are billions of bacteria on Earth, and they’re everywhere. Bacteria are on every surface on the planet, and even live in the soil underground. Most bacteria are actually quite harmless to humans. They spend all of their time eating, resting, and making copies of themselves. But when bacteria decide it’s time for lunch, what do they eat? We asked microbiologist Daniel Bond to help us find the answer.Got a question that’s colonizing your brain? Send it to us at BrainsOn.org/contact, and we’ll send an answer right BAC-ter-ya.