Hard packs behind baby’s ears may be caused by lymph node swelling behind the ear, dermoid cysts, etc., and can be referred to ENT or pediatrics. 1. The baby suffers from otitis externa, otitis media, mumps, etc., which can cause the lymph nodes behind the ear to swell due to inflammation stimulation, thus resulting in the manifestation of a hard bag behind the ear, but according to the different causes of the origin, it may also be accompanied by other clinical symptoms and manifestations, such as pain in the ear, discomfort, pus and fluid flow in the external ear canal, and so on. 2. Congenital dermatoid cyst is a kind of malformation tumor, often located in the subcutaneous, mostly seen in infants, but usually soft, can not be accompanied by other discomfort, mostly using surgical excision for treatment. Baby ear behind the hard bag, it is recommended that the child to the hospital otorhinolaryngology or pediatrics, improve the relevant examination, a clear diagnosis for targeted treatment.