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

After the last raindrop falls, Meena and her mother head out to their garden, which is bursting with vegetables and flowers. But it’s not the produce Meena is curious about. It’s the microbes in the soil (which give it that earthy smell), in the compost pile, on our bodies—everywhere!—that make Meena wonder. How do they live? What do they eat? Where does Meena’s own microbiome come from? Comparing communities of microbes to a bustling city, where everyone has a job to do, Meena’s scientist mom answers her questions as they weed, pick vegetables for a neighbor, eat a snack at the picnic table, and end the day with a bubbly bath. Physician-scientist Dr. Majdi Osman introduces lovable Meena during a day of eye-opening exploration, while Teresa Martínez’s captivating illustrations capture mother and daughter from perspectives ranging from microscopic to aerial. Back matter includes a list of resources and an author’s note about the momentous role of the microbiome in our health and development.