Everyone is assuming it is a North American species. It could easily be a Asian or Russian or even Europeon. HELP first off juvenile is just a name for how many posts a person has. Their name is th bold print in the top left so your name is HELP (funny
)! Do you have access to a digital camera? Can you post a pic of what it looks like? If not, after it sheds maybe you can describe it to us. If it has been eating frozen mice then that is what you should feed it. Buy a frozen mouse from a pet store. Take it home trough it in a container and thaw it out under the tap with some luke warm water. Make sure it is thawed fully. If you are not comfertable with the snake you can just drop it in the cage and the snake will find it. Sit back relax and enjoy the show. After you feed it a couple of times you will get used to it. I take it this is your first snake. Could you describe it's cage better then we can tell you if you have everything you need. There is a lot to learn so just keep reading up on rat snakes but identifying it will help to determine what kind of care it needs.