It depends on the species - and the size of the new-born. Most of the commonly-kept species (such as corn snakes or king snakes) will feed on 'pinkie' mice (new-born baby mice). Gradually increasing the size of the 'food' as they get older.
pinkies and small mice small lizards,frogs,and anything that they can over power and consume
If you want to joke around...
probably a black rat.
gardner snakes eat dugs and small baby snakes
Most rat snakes prey heavily on rodents, but they also eat frogs, lizard, small birds, small chicks and eggs.
no
Baby garter snakes will eat small earthworms and live fish or tadpoles.
no
sometimes
Black snakes are considered a as consumers because they eat meat.
Full-grown rabbits are rather large for most snakes, but many snakes will prey on baby rabbits, and some of the larger snakes can eat adult rabbits.
Garter snakes can eat ants but they are more common to eat other things
Water
maybee
they eat insects when they are smaller but sometimes grow into bigger snakes and start eatine baby mice