Some ball pythons stop feeding during the winter months. It is called winter anorexia and is not unusual behavior. This may be related to shorter hours of daylight during winter months.
If your ball python shows any signs of illness during this time such as high weight loss, breathing open-mouthed or other signs of respiratory distress, it should be seen by a herp veterinarian.
If your snake does not resume eating by spring, it should be examined by the herp vet to determine the problem.
Note: It’s best to feed your snake fresh-killed or frozen/defrosted prey. Snakes have been badly bitten by live prey protecting themselves.