The infant boy was born at the hospital on June 20 but since he weighed 1.25 kg, which is considered underweight, he was shifted to the special care unit specially meant for the treatment of neonatals.
His family are residents of Pathraitha village of Sheikhpura district.
Confirming the incident, civil surgeon M P Singh said the red ants were found in his navel in the afternoon today.
He, however, did not make it clear whether the infant was dead at the time.
The newborn's father Bhushan Yadav, a daily wage labourer, alleged that the infant had died due to the negligence by the hospital authorities, specially the nurse who was attending the neonatal unit.