The premiere book in the STEM for Our Youngest Learners Series introduces the Infant Toddler Inquiry Learning Model, a new way to think about how young children (birth-age 3) explore, think, and learn STEM concepts. The book also demonstrates how the Inquiry Teaching Model can guide teachers in implementing STEM experiences for this age group. Accessible to educators from a wide range of educational backgrounds, this resource is designed specifically to help guide the integration of STEM experiences into the early childhood curriculum. Readers will see how the model works in real life; how STEM topics can be naturally embedded in daily routines and activities; and how to observe, understand, and interact with children as they explore. This accessible guide presents content and pedagogy aligned with what is known about how children learn and also addresses the challenges educators encounter when implementing STEM with infants and toddlers.