Did you know there are more microbes on Earth than stars in the universe? That some five million microbes live on your hand? A child’s curiosity helps her understand why these tiny organisms make such a big difference in her life.

After the last drop of rain falls, Meena and her mom head outside to their garden, which is bursting with veggies and flowers. But it isn’t the produce that Meena is curious about. It’s the microbes in the soil (giving it that earthy smell), in the compost pile, in our bodies—everywhere!—that have Meena wondering. How do they live? What do they eat? Where did Meena’s own microbiome come from? Comparing microbe communities to a bustling city, where everyone has a job to do, Meena’s scientist mom answers her questions while they garden, gather vegetables for a neighbor, have a snack at the picnic table, and end the day with a sudsy bath. Physician-scientist Dr. Majdi Osman introduces the adorable Meena during a day of eye-opening exploration, while Teresa Martínez’s engaging illustrations capture the mother-daughter pair in perspectives ranging from microscopic to bird’s-eye view. Back matter includes a resource list and an author’s note on the far-reaching role that the microbiome plays in our health and development.