Arlington Montessori House (AMH) is known as the "Hippo House" by the families of its students. AMH follows the Montessori philosophy of teaching, allowing children freedom to learn within limits. AMH has two classes of 28 children of mixed ages. Each class is taught by a teacher and an assistant. AMH is on a three-year program, and expects their families to enroll their children from age three until kindergarten. AMH is parent-run, and the parents are involved in all aspects of the school.