Occasionally an adult rabbit will be found dead near a known nest. The dead adult might or might not be the actual mother. There are two ways that a nest can be tested to determine if the mother is still caring for the babies.
First is the string test. Place two pieces of yarn or string loosely over the nest in the shape of an “X.” Because the mother mostly visits at night, this should be done in the early evening. The next morning, check the nest to see if the yarn has been moved. If the nest was untouched, the babies have been orphaned.
Another test is to pick up one or two babies and look at their bellies. In their first week of life, a cottontail’s belly skin is very thin and partially transparent. If they’ve been recently fed, there will be a light-colored triangle in the center of the abdominal area. This is milk in the stomach, revealing that they have been recently fed.
Keep in mind that bunnies slowly digest the milk so this milk can be observed for up to twelve hours. A recheck twelve to twenty-four hours later will assure you that the mother is still returning and has fed the bunnies.