Many infants with special needs, such as with Down syndrome, cerebral palsy, and autism have delayed independent mobility due to weak musculature and/or poor coordination. Children with mobility impairments often do not use powered chairs until the age of five, as per current medical practice. Consequently, these children spend considerably less time moving independently around in their environment compared with typically developing children of the same age. Lack of independent mobility may result in delays in their cognitive, perceptual, social, and emotional development, which are well correlated with locomotion. This paper describes a novel mobility interface for the robot to explore the environment when infants are placed in a prone position. Infants can maneuver the robot through a drive interface that utilizes a camera to detect the motion of markers attached to their legs. We expect that infants will learn to drive the device by swinging their legs. Specifically, this paper demonstrates feasibility of this drive interface using data from two infants. Future studies will determine how infants can be trained to drive a robot purposefully and how such self-generated locomotion affects their long-term development.