The recommended diet for a pet juvenile rat snake is mice, but it can also be fed chicks or rats. In the wild, juvenile rat snakes eat rodents, small lizards and sometimes small frogs.
Mice for feeding snakes are readily available at pet stores; frozen mice, thawed before feeding, are a good choice. Live mice may be purchased and fed to a juvenile rat snake, but the feeding must be supervised, since the mouse could injure the snake. It is best to remove the snake to a different habitat for feeding time so that it does not associate its tank or owner's hand with feeding. In the wild, rat snakes use their powerful bodies to constrict their prey before consumption.