Babies like to spit out their tongues may be caused by physiological factors, or may be caused by pathology, such as underdevelopment of the brain, oral ulcers and so on. 1. Physiological factors: infants are in the period of physical development, the capacity of the oral cavity is small, the development of muscles is incomplete, salivary gland secretion, swallowing function is not all will lead to saliva overflow, cause the child to spit out the tongue phenomenon. Infants in the oral sex period, like to use the tongue to feel the external stimuli, at this time the child often shows the behavior of the tongue. 2. Pathological factors: Inadequate brain development and delayed development of the nervous system in infants can lead to mental retardation, tongue out, seizures and other symptoms. Mouth ulcers can cause pain and ulceration in the mouth of the child, and the child often spits out his tongue to relieve the pain. When a child develops an obvious abnormality, he or she should go to the hospital immediately.