This study investigates how young children master, construct and understand intelligent rule-based robot behaviors, focusing on their strategies in gradually meeting the tasks' complexity. The wider aim is to provide a comprehensive map of the kinds of transitions and learning that take place in constructing simple emergent behaviors, particularly for young children. Six kindergarten children participated individually in the study along five sessions. Regarding modes of engagement, it was found that the children conducted intensive and extended playful investigations of the robot's behaviors, interacting with it in a variety of ways; it was also found that their constructions were planful and anticipatory, as they could simulate how the behaviors play out even prior to running their programs. Three kinds of transitions were found in the children's comprehension of the system: one involved adaptation to the formal language; the second, coordination of multiple spatial perspectives; and the third involved a shift from viewing rules as one-time events to their view as recurring and continual descriptions of a process. Finally, it was found that the children employed two strategies to reduce the amount of information in the system: "pruning" involved ignoring part of the logical structure and focusing on another; "fusing" involved coalescing several rules or functions into one. These results are discussed with respect to previous literature on children's programming and with regards to understanding and supporting young children's learning through their construction of adaptive autonomous behaviors.