Two and a half year old baby’s late-night irritability and tantrums may be caused by adverse environmental stimuli, calcium deficiency, indigestion and other reasons. Can be taken to adjust the sleep environment, calcium, dietary adjustments or take probiotics and other medications. 1. Adverse environmental stimulation: If the baby sleeps in an environment with too high or too low a temperature, loud noises or strong light, it will stimulate the baby and lead to the baby’s late-night irritability and tantrums. It is recommended that parents should adjust the sleeping environment in time, maintain the appropriate temperature and humidity and brightness, so that the child has a good atmosphere, thus alleviating the baby’s symptoms. 2. Calcium deficiency: If the baby lacks calcium, the function of the cerebral neural cortex will be abnormal, over-excitement, which leads to late-night irritability tantrums, it is recommended to eat more calcium-rich foods, and in severe cases, calcium supplementation can be prescribed by the doctor. 3. Indigestion: The baby’s gastrointestinal digestive function is weak, too much food or other factors stimulate, easy to indigestion, resulting in late-night temper tantrums. Parents are advised to adjust the diet in time, eat easy-to-digest food, and take Bifidobacterium triplex if necessary to regulate. Note that the above drugs should be used under the guidance of a doctor, avoid unauthorized use of drugs to avoid adverse effects. If the baby’s symptoms are not relieved by the above methods, it is recommended to consult a doctor in time to deal with and treat the cause of the disease.