The relative influences of sensorimotor systems, body morphologies, and environmental features on infant rat behavior were assessed using robotic and simulated agent-based models. Rat pup behavior has been long thought to be produced or mediated by sensory and central processes. However, after demonstrating the inability of a reactive sensorimotor architecture to reproduce rat pup behavior, I show that a random control architecture in a morphologically similar robot embedded in a scaled environment can reproduce behaviors seen in infant rats. The robustness of this novel hypothesis regarding the generation of rat pup behavior was tested by incorporating increasing realism into the model. Simulated agents were created with more appropriate kinematic schemes and more realistic body morphologies. Decoupling lateral (rotational) from forward (translational) movements allowed for the creation of a new behavioral parameter, the lateral:forward ratio, which I show differentially captures individual rat behavior at multiple ages. Morphological analysis reveals the critical importance of two-degrees of freedom of body motion in capturing the dynamics of groups of interacting pups. Agent-based models continually demonstrate that behavior and cognition are the emergent products of (1) embodied agents that are (2) dynamically embedded within an environment and (3) equipped with simple sensorimotor rules. I conclude that (1) and (2) may play a larger role than previously thought in the generation of complex behaviors. (PsycINFO Database Record (c) 2016 APA, all rights reserved)