Infants always sticking out their tongues are considered to be related to physiological factors, and may also be caused by dental development, oral ulcers and other factors. 1. Physiological factors, infants always sticking out their tongues mainly because the swallowing function of infants is not fully developed, after secreting more saliva can not be swallowed quickly, this symptom may occur. 2. Dental development, infants in the process of growing teeth saliva secretion exuberant symptoms, may stimulate the oral mucosa and the tongue, so it will also produce always sticking out the tongue. 3. Mouth ulcers, if the baby has mouth ulcers, the oral mucous membrane is damaged, which may cause discomfort to the baby and this symptom. Infants always sticking out their tongues, there may also be other reasons, such as congenital stupidity, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.