This document discusses the sensitive period for movement in children from birth to 2.5 years old. During this time, children are highly motivated to move and develop motor skills as they progress from rolling to crawling to walking. Their need for movement seems limitless during the toddler years as they work to refine their coordination and control. The environment should accommodate this need for free exploration and movement with opportunities to carry objects, climb stairs, and get in and out of furniture independently.