We found a dead mama opossum with only two babies alive. Their eyes are open, they don't seem injured, and they are 3 inches long at the most not including the tail. They don't seem to pee or poop on their own I haven't seen them do it when I try to stimulate them either. Right now I have been using pedialite and water and also 1 part puppy formula that starts with an e I can't remember the name, 1.5 parts water and 1/3 part heavy whipping cream. They aren't used to it yet they will lick it up a little bit but not much. Is that normal? What can I do to get them to eat? Also how much and how often should each one be eating? Any other tips would be greatly appreciated.