If you find an injured or dead female opossum, it's possible that she will have babies in her pouch. Check the opening on her tummy for babies. Even if she is dead, the babies may be alive. Keep babies warm and in a moist environment while delivering them to a rehabilitator. Opossum can act very aggressive but it's mostly bluff. Be careful if you find an adult injured opossum. Many people don't like opossum but they are actually nice animals and help the environment by eating slugs and cleaning up a lot of unwanted things in our environment. Give um a break and help them!