Paige has knack. She can pile just about anything into a tower, a line, or a path. She gathers colors, sizes, shapes, and objects and puts them in their place. Toddlers often sort as a way of learning similarities and differences, but when this behavior interferes with other activities, Obsessive Compulsive Disorder might be the reason. Toddlers with OCD get overly upset when their routine changes. Repetitive behaviors like washing, counting, or lining up objects when used to control their world may be a sign. Like most children with OCD, Paige doesn't understand why she likes her things in order. She only knows it feels right for her things to be just so.