All babies instinctively use their body to send us signals that they are trying to communicate to us by using facial expressions, crying, noises, and gestures. Teaching a baby sign language helps the baby to learn how to communicate with their parents.
For example, all babies are trying to get our attention by making noises, crying, tightening/tensing their body, raising arms to be picked up, smaking lips when hungry, or spitting out foods when he or she had enough or not liking the food. Or pointing out to an object that he/she wants and the baby would arch his/her back,crying,grunting, or clentching fist to demonstrate anger as the baby tries to communicate he/she does not want.
By expanding your baby communication with you will help your baby to tell you exactly what he/she wants with one boby language and sign language. This would eliminate a huge stress of frustrations between the parents, caregivers, teachers and others.