you give it a gentle tap.
babies do not understand syringe feeding and they must be force fed. since they cannot smell food in a syringe they will try and get away. if you cannot do this correctly, you can try a tiny spoon with soft food or the formula you are using in the syringe and touch the birds beak with the spoon and hope it can smell or taste it and will open up for it. otherwise you must force feed the bird. in time it will understand that the syringe is food and accept it readily.
newly hatched chicks rarely feed in the first 10-15 hours. during this time 