The causes of children always drooling, mainly include the following aspects: first, due to the physiological characteristics of children. Drooling occurs when teeth erupt before children are two weeks old, especially when children have a shallow bottom of the mouth at this time. Secondly, symptoms caused by children suffering from mouth ulcers. If there are ulcers or herpes in the mouth, it can also cause children to drool all the time, and due to the pain in the mouth, symptoms such as poorer appetite for food can occur. Finally, the symptoms are caused by the child’s low intelligence. A child with a significantly low level of intelligence may drool frequently, and may have other symptoms of delayed brain development, such as a delay in learning to read and walking.