As speech therapists, we are frequently asked by parents and teachers whether it is “normal” for babies and toddlers to put everything in their mouths. While mouthing can look concerning, it is often a developmentally appropriate behavior  and an important foundation for feeding, speech, and self-regulation. These early sensory-motor experiences lay the groundwork for later cognitive, motor, and language development. Why   does mouthing occurs and when should it decrease? 1.