The rule of thumb is to rescue a baby opossum if it is less than 8 inches from nose to butt. Use a 6-inch dollar bill as a handy ruler. They are extremely vulnerable to predators. Often, they will fall off the mom while traveling. Mother opossums never return for the baby.
Typical size of baby opossum that needs immediate rescue.
If the baby opossum is:
  • longer than the dollar bill by two inches, appears to be healthy, has no injuries, has no visible parasites, is not attracting ants or flies, then the opossum does not need rescuing.
  • If you must chase an opossum to catch him and he is 8 inches long, he does not need to be rescued!
  • If the opossum is without a mother and appears to be thin and lethargic even though it is 8 inches or longer, please consult with the DFW Wildlife Coalition hotline or a local rehabilitator. Opossums are susceptible to flea anemia and the opossum you found might need a helping hand.
This video demonstrates how baby opossums can fall off the mother and she not be aware.
The opossum I found is pink and is only a few inches in length. What should I do?
Sadly there isn’t much you can do to help pink baby opossums. Pink baby opossums have a very low odds of surviving in a rehab center. To understand why you have to understand how an opossum’s life begins. An opossum is born after a 12 day gestation period. A newborn opossum is the size of a jellybean and will crawl into the pouch where it will then attach to the mother’s teats for 24/7 nourishment for the next two months. Inside the pouch they are kept a consistent temperature, as if in an incubator. Because it is impossible for a rehabilitator to match the perfect conditions found in a mother’s pouch, a baby opossum that is pink has low odds of surviving in a rehab center.
A video of baby opossums in the mother’s pouch.