Around 5 months, most babies become more skilled in their reaching and grasping attempts. This includes the ability to grasp moving objects, which in part depends on proprioceptive information. Proprioception uses sensory information from the muscles, tendons, and joints to help a person know where his or her hands (or feet) are in space without having to see them. Experiments have shown that infants at 5 months can reach for glowing objects that move in the dark. Babies’ growing curiosity and abilities lead them to try new things, so parents and caregivers should arrange the environment to minimize the possibility of falls, bumps, and bruises that can result from unexpected new movements. Also, babies at this age should never be left alone on a changing table, bed, couch, or other item to prevent dangerous falls.
Robin, D. J., Berthier, N. E., & Clifton, R. K. (1996). Infants’ predictive reaching for moving objects in the dark. Developmental Psychology, 32, 824